Image copyright Publicity Image caption 'Every book is hard to write, everybody reaches a wall, whether it is a plot hole or a scene that you can't get past. So you've just got to get to the end,' says Sophie Kinsella

Sophie Kinsella is the bestselling author of the Shopaholic series, Can You Keep a Secret?, The Undomestic Goddess and Wedding Night.

Her novels have been translated into more than 40 languages, and Confessions of a Shopaholic, has been made into a film starring Isla Fisher.

Here are Kinsella's top 10 tips for being a bestselling author.

1. Always carry a notebook

Carry a notebook everywhere and write down everything that springs to mind, even if it doesn't seem relevant at the time. You can do a lot with a passing thought or a little bit of overheard dialogue.

Get into the habit of looking at life like a writer and writing it all down. Don't worry about what "it" is going to be yet, just write it down as a habit. Because then, when you do have your big idea and want to write a book, you'll already be used to that process and have material to work with.

2. Think "what if" and read

Start to see the world in a "what if" way and keep your possibilities for a story. Teach yourself to take a tiny little nugget of substance and extrapolate and tease it out into something else, have fun with it and see the potential.

It can seem tiny and insignificant but if you can sense the grain of a story there and keep your mind open to those possibilities, you will constantly come up with new ideas.

Reading is vital if you want to be a writer, it's essential. I've been a bookworm ever since I was a child, I was the type who would read a cereal packet over and over rather than make conversation at breakfast!

3. Write the book that you want to read.

People often think that they should write to please someone else, whether it is to please the audience, or critics, or a readership. My instinct has always said that you can't second guess anybody else.

Image copyright Publicity Image caption 'What you have to do is find your story and find your voice,' says Sophie Kinsella

What you can do, is think if you were a reader, what would you want to read? One way to visualise that is to go into a shop and imagine the book that would make you want to grab it off the shelf.

The chances are that if you would grab it off the shelf and be excited to read it. then other people would too. So always start with yourself, write something that will please you.

4. Don't talk about what you're writing

I am very secretive when I'm writing a new book. I think that writers are very fragile, they're like butterflies or perhaps moths; they can be easily crumpled. If you're very sensitive, which I am, it only takes a raised eyebrow or a chance remark about an idea for you to lose confidence in it.

I think it's much better to let these things gestate in private, that way you can be free to try stuff out without any fear of being judged or worrying whether it might not work. The minute you put it out there and ask for opinions from other people, it will just get in the way of your creativity.

The only person I let read my work when I'm writing is my husband and we've had this arrangement long enough that he knows what not to say! I think a work in progress is a very precious and nebulous thing and it can be easily destroyed so protect it!

5. Forget about genre to find your voice

I think that one of the hardest things as a writer is to find your voice. See what you enjoy writing, because let's face it, you're going to be spending a long time in this zone, it had better be something you enjoy and something which you can do.

Don't be afraid of a few false starts. I once tried to write a thriller and I remember my agent saying that the plot was ok but that all the characters were far too nice. I'd written about all these nice middle class people walking around killing each other!

Don't sit there thinking what genre should I write in, perhaps you'll invent a whole new one! Instead, start off by thinking I'm going to write a story and wait for other people to put it in a genre. What you have to do is find your story and find your voice.

6. Just get to the end

It's the hardest thing and it's the most important thing because so many of us have ideas for books. The first stage is actually write it instead of just talking about it, and the next stage is to keep going until you get to the end.

Everybody, no matter who they are gets to the middle of a book and thinks crikey, I've had enough of this. You get bored with your story and your characters, you hate them all, you can't think why you started this wretched story in the first place.

The truth is, every book is hard to write, everybody reaches a wall, whether it is a plot hole or a scene that you can't get past. So you've just got to get to the end. Even if it's not the greatest draft, if it needs rewriting fine, at least you have a book to rewrite.

7. Walk and drink cocktails!

Everybody gets stuck. I find cocktails very helpful! And that's the truth, if I get stuck, I'll go out with my husband and we'll order cocktails and talk while we drink them. By the end of the evening, we've always ironed out the knot.

I find it loosens you up and also it turns it into a fun project, there's nothing worse than sitting grimly staring at a screen, you must get out.

The other thing to do is go for a walk, walking seems to free up the cogs of the brain like nothing else. You can sit at your desk for two hours, feeling wretched because you can't find the solution, then you give up and go for a walk and it comes to you straight away.

8. Plan your books

For me, the planning stage is vital and it takes months, if not years. When I'm writing a book, I do it in my office, but when I'm planning a book I like going and sitting in coffee shops. I like the buzz and I like being surrounded by people, but remaining anonymous.

I write my plot points on file cards and Blu Tac them to the wall. Then I stand back and look at the terrain of the story and decide whether I like it and if not I can just move them around. I find that very satisfying - it's a bit like doing a crossword puzzle!

The truth is you can plan and plan but during the story, something will change, that's just the way it is. But I find starting off with structure and a beginning, a middle and an end is vital.

9. Get a great agent and consider a pseudonym

I think I've written 20 books in total now and I've always had the same agent. Having an agent, for me is the best thing I've ever done, because she's guided me, she's been a friend, she's dealt with all the business side of what I do and I wouldn't have known where to start without her.

There are lots of advantages to having a pseudonym. It gives you a bit of privacy so you can have an official name and a home name. And I don't think there are many careers where you can just completely reinvent yourself every so often - it's wonderful.

10. Write the next you

Everyone has got a story to tell and everyone can learn and improve their writing. There are some elements of writing which can definitely be taught, a sort of craft and you should always try to learn and improve. I am still learning with every book.

I don't see why anybody shouldn't write a book. There is nobody who is not interesting in this world, so why shouldn't they tell their story?

You write what you write. You can't decide to write a certain book, I believe your writing finds you. So don't go thinking, I'm going to write the next Da Vinci Code or the next Stephen King. Write the next you. You are going to be the next big thing!