Last month, I attended a City Lit course entitled 'How to impress a publisher', which promised to reveal all about how to get a novel from your hard disk to a shop shelf. The good news is that it delivered exactly that insight. The bad news is that I'm now faced with much more work to do.

One of the main shortcomings of my novel is its length. At around 60,000 words, it falls short of the standard 90-100k length. This is important for an entirely pragmatic reason: there is an expected standard width for paperback novels, all of which retail for around £8 each. A shorter novel will have a thinner shelf profile and that is enough to discourage publishers, because potential buyers will be put off at the smaller size - and having to pay the same price for it.

It was made very clear to us that publishers and agents are looking for any excuse to reject submissions. The top agents can apparently receive 300 manuscripts every week but might only take on three or four new clients in an entire year. The importance of fulfilling the standard industry expectations is essential to give yourself the best possible chance. Submitting a short novel is a fast track to getting a rejection letter.

That means I need to extend the length of my novel by at least 25%, which is more than six months' work at my current rate. Therefore I won't get it finished before my 40th birthday in July - which was my original ambition. But an arbitrary date is no good reason to undermine whatever (slim) chances I have.

So now I have to figure out how to add more to my novel. Once I've finished my current round of revisions, I intend to write a single-page synopsis of the book as it stands. There are already some bits that I know could be fleshed out. In addition, I will probably need an additional subplot - and I have some initial ideas about how that could work.

The rewrites I am doing at the moment are going quite well, and are making the book stronger, I think. Something else we were told on the course was that you had to make the submission as good as it can possibly be, rather than sending in an imperfect version and implying there's room for improvement.

They also told us that a £5,000 advance would be considered very generous for a first novel, and that a bestselling debut is only sells around 20,000 copies, with a royalty of only 3% of the cover price. Evidently nobody is in this for the money ...