Twenty years in the publishing business have given Liz Puttick an extremely sharp eye for a bestseller. Having been editorial director of the Thorsons mind, body, spirit imprint at HarperCollins, she quit in 1995 to start her own non-fiction agency. Non-fiction is booming at the moment, she told us. It’s no longer the poor relation of fiction. Half of the list of top selling books in The Bookseller is non-fiction. There are more prizes for it these days, too, such as the Samuel Johnson £30,000 prize. At literary festivals, up to 90% of the talks are on non-fiction subjects.

This roaring success does have a downside, though, and that is that more and more writers are becoming attracted to non-fiction as a means of getting published and making money, so non-fiction agents like Liz are being inundated with ideas and the competition is fierce. But before you start feeling too downhearted, here is Liz’s 4-point plan for improving your chances. It’s all to do with being professional and doing your homework.

1. Study what is currently selling well and choose the right subject that is both topical and saleable.
2. Do your own market research. Identify your core readership and work out how to promote yourself and reach them.
3. Look on the Amazon website and check out the competition, then make a case for how your own offering is better.
4. Improve your author profile. Setting up your own website is a good way to start. Money expert Martin Lewis, who is one of Liz’s top authors, did this and now has over one million subscribers to his financial tips newsletters.

As well as these tips, Liz recommends any aspiring non-fiction author to write a winning book proposal that looks polished and professional.

The kinds of subjects that are doing well at the moment are books like Longitude, that sparked off a whole new genre of narrative non-fiction. Personal memoirs of overcoming a terrible childhood are still in vogue and so are quirky reference books such as the current bestseller, Why Don’t Penguins’ Feet Freeze?

When it comes to memoirs, Liz said that key words in the descriptions of the latest publications mentioned in The Bookseller were: “courage, grit, passion, poignancy, bleak, harrowing, tragic.” Get all those in and you might have a winner on your hands.

Her website is www.puttick.com.