If you want to get shortlisted for a literary prize, there are a few tricks you need to know. I write this as one of the judges of this year's Orange Prize, serving under the radiant Joanna Trollope. Our excellent shortlist was released yesterday.

And before you write in to tell me how awful it is to have a women-only book prize, please note that absolutely the first thing I will worry about once we've addressed women earning less than men throughout their working lives and, equally, men dying younger than women, will be gender imbalance in book prizes.

To make it on to the shortlist, you need to be a great writer. This may seem obvious, but you'd be surprised how many people think that because they and their friends like their book, everyone else will too. The existence of a bad review of virtually anything clearly disproves this theory, but people cling to it.

You need to come up with a story that people who read a lot of books haven't seen before. I read something like 60 books in the first chunk of Orange judging. On top of the books I read for reviewing, this means I probably read 80 books in four months. Sometimes it felt like I was reading the same few books over and over. I read a lot of coming-of-age stories, a lot of Second World War stories and a lot that felt like someone was writing their memoir, disguised as a novel.

The books that stood out were either written in vastly better prose than the rest or told a story from a dramatic new angle. This is especially true of historical fiction: if you're going to retread the ground of thousands of other books and films, you need to say something new, and say it well.

The holy grail of the shortlist is a book which is both about what it seems to be about, and also about something more. This is where the disguised-memoir novels tend to come unstuck: they are always about the narrator's life, and nothing else. Whereas the shortlisted books are about something bigger than their characters' experiences: love, either unrequited or returned in spades, infertility, familial bonds and how they stretch across time and space.

The shortlist is chosen by five judges. We negotiate and compromise, like the adults we are (in spite of my best efforts to have the list chosen by arm-wrestling). There are books that didn't make the final cut which I loved. The other judges all feel the same, I'm sure. But the list has to reflect the tastes of five people, so a shortlisted book needs to have broad appeal.

It also needs depth: I'm now re-reading books I've already read a couple of times, and it's now that any flaws tend to shout at you. But equally, the really great prose, or the beautifully drawn character, seems even better. Now we have the trickiest choice of all ahead of us: picking the winner from six such different books.