First piece of advice: 'reconsider'. For a start, it's not remotely well paid. I believe that the current figures tell the misty-eyed that, in fact, the average, published writer in the UK earns about £8,000-£9,000 a year from it. People's perceptions are warped because of news stories reporting only the hugely-rare exceptions - reading the papers, you'd think almost every first-time author got a million-pound advance. Next, do not do it because you have some mad idea that it will validate you as a person in the eyes of the world. Never even consider fantasies about cascades of breathlessly-awed reviews. Instead, have a quiet think about (if you manage to get reviewed at all - which is an uphill struggle for the publishers, let me tell you) whether your fragile, in-need-of-third-party-bolstering self-image can survive reading someone in the national press saying you're a tiresome, illiterate moron. Because they will: that's simply a fact of varying personal tastes (I even read someone opining that Patrick Suskind's Perfume was 'a waste of paper' the other day - unbelievable). And when someone doesn't like a book, they really love to lay into it, and the author personally, as savagely as possible. Consider writing only if you're doing it for yourself, not because you want to be told you have worth or 'need to be loved'.

OK, in the sweepingly certain knowledge that you'll all utterly disregard the above, let's get down to practical advice.

1. Get an agent. I can't stress this one enough. It's not completely impossible to be offered a contract without having an agent (as it happens, I didn't get one until after I'd received offers; but then I wasn't trying to get a publishing deal anyway, so I'm a doubly bad example), but it almost is. The brutal fact is that publishers get sent a crushing number of manuscripts every day, and the very first filter they apply to these is 'Does it come from an agent?'. The logic being, if an agent is prepared to invest a little time and effort in the thing, then it's worth their looking at it too. If an agent isn't, then it's rubbish. And it's no good putting in a covering letter explaining why you happen to have decided to bypass getting an agent: all that means to a publisher is that the manuscript in front of them might be OK, or it might be a complete waste of their already overloaded time. So, why bother, when there are hundreds - thousands - of manuscripts spilling from their shelves that definitely do have an agent's backing? Get. An. Agent.

Having said that, getting an agent is no easy task in itself. Again, I was sickeningly lucky. When I was looking for an agent I already had written offers sitting in my surprised lap, so it was rather a case of asking, 'Um... would anyone like to pop by and take ten per cent of one of these?' Getting an agent is usually terribly difficult - and not without the potential for trouble: I, personally, would never go near an agent who asked you to pay them to read/comment on your stuff. You can find agents listed in the Writer's Handbook. Obviously (this applies to publishers too), approach them sensibly. Don't send your sci-fi fantasy epic to an agent whose WH entry says they don't accept unsolicited material and specialise in historical romance and pet books. A usefully 'unofficial' list of agents is here: http://everyonewhosanyone.com/aguk.html It's a little out of date, but still informative.

2. Publishing is a business. Say that out loud. Even the chief commissioning editor at a publisher is unlikely to be able to run to you with a contract wriggling excitedly in her hands on her say so alone. The question asked of manuscripts in publishing houses the world over is not, 'Is this good?' but, 'Will this sell?' I'm not saying you should 'write to be commercial'. Quite apart from the fact that I'd rather not write at all than write stuff I didn't like just because I thought it'd be popular (and so should you - or why write in the first place? If you're not doing it for the love of the thing itself, then you'd be better off getting far more money and far less grief working in conveyancing instead), it's almost certainly doomed to look like nothing but terribly-forced tosh written because the author thought it'd be commercial. And thus you're twice damned. What I'm saying is consider whether what you're writing will be a success. Some things won't. Some things are dead before you type 'Chapter 1' - biographies of your wonderful grandmother and her interesting life, for example. Personal struggles to overcome adversity? No one gives a bugger about your courageous triumph over illness/deformity/prejudice/depression/addiction/whatever unless you're already at least a mid-level celebrity, OK?

Before it even gets a chance to pass before the weary eyes of the general public, publishers have to persuade bookshops to stock copies of your novel. In today's sprinting, sound-bite world, everyone wants to hear the novel's premise slapped down vividly in two sentences. So, think about how you'll 'pitch' your idea - practise desiccating Madame Bovary, Northanger Abbey, etc. down to movie poster-style shoutlines, if you want (it's a fun party game anyway) - and be aware that, of the two ideas boiling inside your brain, the instantly understandable and intriguing High Concept one is probably going to give you the better chance of getting your first deal than the gentle character study of two sisters living on a farm against the backdrop of rural Wales in the 1860s.

3. Submitting manuscripts. Do this to an agent if you can, as stated above. Whether you're sending it to an agent or a publisher, though, keep it brief. There is absolutely no need, nor benefit, in sending the completed manuscript right away. The standard practice is to submit a synopsis, three chapters (they needn't be the first three), and a covering letter. The covering letter should be professional. List biographical details - especially those that might help a little; 'I've had short stories appear in various publications', 'I stole Shergar', 'I live across the road from Nicole Kidman and got the idea for this book after keeping a powerful telescope trained on her windows for the last four years', etc. Do not ramble on about how you've wanted to be a writer since you were a small child and the way your lovely, late Aunt Betty always encouraged you. An agent can easily have to go through twenty new submissions a week (in addition to all her other work): long, wistful autobiographies disguised as covering letters are likely to piss her off - she simply wants to get on with it so she can get away in time for her yoga class.

4. Don't send your work to me. Sadly for me, I don't have the time to read stuff. Luckily for you, my opinion carries no influence with anyone anyway. And, overwhelming both of those things, I'm apparently clueless, it seems: books I think are wonderful often whither on the shelves, while the writing of a good many massively-bestselling authors of recent years has done nothing but fill me with a howling urge to go round their houses and beat them into ICU beds in the dead of night.

5. The Internet. Writing for the Internet is entirely different to writing a novel. Also, anything decent you put on the Net will get stolen. Fact. So, if you think you can do a Webpage that will give you some kind of profile, fair enough; but regard it in the same way as you would running naked across the White House lawn as a way of getting publishers to take notice of you. Putting your novel online in the hope that someone will pick it up is doomed for so many reasons that it would wear out my knuckles to sit here typing them all.

6. Self or 'vanity' publishing. With a few exceptions - targeted local books, say - this is simply a way of transferring your money to someone else's bank account. Would-be writers often think, 'If I could just get it out there, it'd sell - word of mouth.' No. As I said further up, even big, established publishers have to work hard to get bookshops to stock their books. Waterstone's simply aren't going to take your stuff, let alone display it where it'll be seen (publishers have to pay thousands for visible locations in the stores).

7. Rejection. If your manuscript is repeatedly rejected, if could well be that it's because it's rubbish. There's no shame in this - I'm never going to appear in any The World's Most Desirable Men lists, for example. Them's the breaks. Brad Pitt might set women panting, but I bet he can't configure a wireless network as rapidly as I can. So, perhaps you can't write, but you're really good with horses or can pack suitcases exceptionally well or something. It all evens out in the end.

However, there's also the possibility that your stuff is being rejected because it's being read by idiots. So, don't be put off too easily. Remember, if - say - Penguin sends your manuscript back with a terse, form letter, it's not the infallible literary voice of an all-knowing publishing house judging you. It's one person. One person, on one day, perhaps after a long, drunken night at a wedding reception, not liking your writing. One author I know hit gold with his first book - New York Times Top Ten Bestseller; big commercial and critical success; set up for the rest of his career. Yet the manuscript for it was rejected by seventeen different publishers before someone saw that it was splendid. Publishing is like that: be realistic, but be resilient.

8. Try to be your own harshest critic. This isn't actually possible - the world is brimming with doltish, bitter individuals sucking desperate mouthfuls of pleasure from criticising people because they hope it'll make them appear clever in the eyes of others. But try. Glare sternly at every sentence you write: 'good enough' is not good enough. Don't use clichés. Don't try - or accidentally allow yourself to - sound like anyone else. If you're being defensive, it probably indicates that you know, deep down, that you have to try to justify things that need support to survive. If every word sings off the page, you'll be less inclined to get angry at those who criticise you, and simply think, 'Meh - what a twat.' The only opinion that really matters to me is my own, because I'm utterly brutal with myself, so if what I've written passes my own tests it's earned its stripes. I think that's best. It helps you write as well as you possibly can. Writing is often called masturbation, but it's probably better, because of the double meaning, to regard it as a form of self-abuse. It flows clearly from this that you shouldn't be fooled by praise either. If you think something you've written is 'Fff' but people are telling you it's actually the incandescent prose of a unique genuis, then it's 'Fff', and that's the end of it.

9. The writing is all that matters. You are its servant. It's not about you; it's about the words. So, never pull back from writing something in the ideal way - or writing about the most interesting things - because you're worried what your mom or the woman at the post office will think about you. People sometimes call this 'honesty'. It isn't - you might be writing the mind of a rapist; it's not you - but it does require a certain amount of, um, 'bravery'. But self-censorship is the vilest censorship of all, because it's a factory designed to produce flavourless, furiously-inoffensive pap.

10. Length. Obviously, a novel should be precisely the length it has to be. As a warning, though, don't imagine that bigger is better in some kind of 'value for money' way. A 'novel' in publishers' contracts will generally be 'about 80,000 words'. Going over that - I know from repeated experience - causes problems. The American publisher tried for months to reduce the length of my first book (100,000 words) purely to make it slimmer to look at - as Americans are put off by thick books, apparently. There are also problems associated with foreign publishers paying translation costs, as well as simple printing overheads. Never mind the literary wrongness of trying to pad out your book to get it up to 200,000 words: even on a purely practical basis it's shooting yourself in the foot.

11. Don't write crap dialogue. The number of writers writing crap dialogue is stunning. It hurts my soul to read it. Think about making all of your writing flow and sound natural, of course, but think about it, then think about it again with dialogue. Then think about it another six times.

12. It's often said that the best thing you can do to write better is to read a lot. I'm not sure that's true, but being aware of other people's work, and their excellence, and their mistakes, and their ideas is very useful indeed. Reading may be the way for you to do that, or it could be that doing a creative writing course helps, or even watching films - analyse the structure of movies, think about how plot points are introduced and how characters are defined. It won't just improve your writing, it'll actually make it easier for you to write too - because you'll know where you're going, what you're trying to do, and it'll help you identify problems (rather than simply having a cold, inchoate, stymieing feeling that 'something isn't working here').

13. Don't introduce eighteen characters and twelve vital plot points in the first twenty pages. Yes, spy and fantasy authors, I'm looking at you. Readers can retain only about four characters and two or three 'things' in their heads until they've really had a chance to get into the book. Bombard them with more than that and they don't simply forget the rest: they mentally collapse due to information overload and lose track of everything.

14. If the dizzy female protagonist finally realises that she's been wasting her time on a succession of stupid, self-centred men, and that her sweet 'friend' David is the person she's really loved all along, then I will hunt you down and spit in your ears. Relatedly, turning up at a fancy dress party, but - Ah-ha! - it's not really fancy dress at all! You/she/he is the only one there in fancy dress, due to a misunderstanding/a lie told by the your/her/his evil rival: no. No, no, no. Seriously, just how many tiresome times do we see these clichés repeated? Writing them yet-a-bloody-gain will succeed in nothing but making me angry. And while you might get away with making other people angry, if you make me angry by sloshing out that lazy drivel I'll break both of your legs, and then return every day for the next month to kick at your crutches.

15. I think I've said enough already, without bothering you with more than fourteen points.

This article first appeared on Mil's website, and is reproduced here by permission of the author. You can also read the interview with Mil Millington that we did a while back. Mil Millington's novels, Things My Girlfriend and I have Argued About and A Certain Chemistry are available from the shops. There's also a third one on the way. For an introduction to Millington, you really should visit Mil's website.