Bestseller is a word which dazzles people. They get dollar signs in their eyes and can’t see what’s in front of them. Bewitched by the fantasy of being run over by a monster pile of cash, they forget that a bestseller is actually a book. The single most useful thing you can do if want to write a bestseller is ignore the crap, the cult, the mystique and the bullshit and start with a clear head and an open mind.

Take a look around you. Books are the seed-corn of popular culture. A book can fairly be called a bestseller if it sells more than 100,000 copies in the home market, but most bestsellers also achieve substantial international sales; most are also translated into the more popular media of film or television, reaching tens of millions of people all over the world. Quite simply, to appeal so widely your book must be about something which is important to that many people.

The essence of a bestseller is its theme, the human core of the book which addresses a universal dilemma or anxiety. Some themes are contemporary, generated by our anxieties about modern society like gender panic, genetic engineering or environmental destruction. Some themes are eternal, dealing with human experiences which in essence do not change, like growing up, falling in love, accepting maturity or facing death. The writer’s challenge is to set them in a new context which will illuminate them meaningfully for people navigating their life passages for the first time.

Because we are all human, whatever fragment of story is floating around in your mind, bugging you at 5am, will contain a theme large enough to sustain a bestseller. Whether you have the commitment and the skill to extract that theme and make a book out of it is another question. As you excavate your characters and construct your plot, push your story out to its fullest dimensions and the theme will emerge. Emotionally, this is hard work; it is always more comfortable to leave the theme buried in superficialities. Same old story - no pain, no gain.

Where in the world (or beyond it) you choose to set your story will depend on where you feel comfortable and where your theme works to greatest advantage. Because there is a lot of correspondence between fact and fiction throughout our culture, the idea of a bestseller almost as a documentary tour of a glamorous, exotic world is very strong. Certainly, it worked for Ian Fleming and John Le Carre, and enabled writers like Michael Dobbs and Michael Ridpath to capitalise on their first careers in hot subcultures.

The classic advice to new writers is to stick to what you know. It is certainly true that many authors ambitious to write popular fiction fail because they attempt a setting which they cannot create with credibility. Writers have created great stories from many mundane and tiny worlds, from Jane Austen’s English villages to Nick Hornby’s testosterone corral. Louis de Bernieres and Michael Ondaatje have painted glorious, intensely coloured and utterly convincing pictures of worlds about which they initially knew very little.

In science fiction, writers like Michael Crichton and J G Ballard have taken germs of modern experience and cultured them into complete fantasies. The power of your imagination is the only real limitation.

Remember that you are a storyteller. The scriptwriter and lecturer Robert McKee says that the story is the real star of a great movie, and in the same way the story is the real hero of a bestseller. You will hear depressing expressions like “narrative-led” or “plot driven”. What they mean is that your story must be a great emotional experience for your readers, something which will overwhelm them, move them and satisfy them. Your story will turn your theme into a drama acted by your characters.

There are never-ending stories, as there are eternal themes, but constructing a compelling narrative is not a matter of following a formula. There is a classical story structure which most of us instinctively understand. Every writer chooses to use the elements of that structure differently. Even if you have chosen to write in a genre, the conventions of that genre exist to be reinvented with bravura - as Anne Rice reinvented the vampire story - not to tie an author to any predetermined plot.

Some books are written from plot to character, beginning with an event or sequence and then discovering the people who make these things happen. Other writers work from character to plot, intrigued by a personality at the beginning and devising events to test the character in action. However you assemble your plot, I would recommend writing it down in the form of a narrative outline. You can then analyse your story, identify its weaknesses and correct them before that becomes a matter of junking 50,000 words.

Keep looking around you. Observation is so important for a writer. Notice people reading on trains and boats and planes. Notice how much of a chapter your partner gets through reading in bed at night. Notice the paperbacks and the cigarettes side by side in your workplace smoking area, and deduce that when their owners take a fag break they will read only for the duration of a Silk Cut. Notice the mountain of stuff on your desk waiting to be read, the pile of Sunday supplements you mean to read but never do. Notice that nobody’s idea of a fun evening is sitting by the fireside reading aloud to their mates.

In advertising, they call it time poverty. Nobody believes that they have the time for anything, including reading, which is fitted into the odd corners of the working day and only enjoyed with any sense of legitimacy as part of the all-in sybaritic experience of a holiday.

A bestseller is written for real people, people whose lives are full and stuffed with choices. Your challenge is to seize and hold your readers’ attention despite their time-poverty consciousness. It can be done. Last year a man was prosecuted for reading a bestseller while driving down the fast lane of a motorway. The newspaper reports did not name the author, but whoever it was certainly knew a thing or two.

A bestseller needs a strong beginning. From the first page, it needs to give the reader a copper-bottomed, bomb-proof, irresistible reason to continue. Most bestsellers also need a hero or heroine, a protagonist who appears at the start and becomes the emotional vehicle in which the reader travels through the story. You may also hear it said that the protagonist of a bestseller should be a sympathetic character; this is not the same as being a nice person. Scarlett O’Hara was not a nice person and Gone With The Wind is the all-time great bestseller, now in print for more than 60 years.

Storytelling is an art, and you need to practise it. Teachers have two great advantages here - the long holidays, of course, and the captive audiences, essential for developing your storytelling skills.

Having induced your reader to begin, you need to hold his or her attention. The same things which make a class slump, daydream, fidget and start chatting will stop your readers following your story. You may know more than you realise about timing, repetition, humour and the attention-grabbing properties of sex, drugs and rock’n‘roll.

Another myth is that all bestsellers are badly written. Nobody likes a badly written book, especially not a publisher, so you should write as well as you can - but simply. When choosing your words, resist the temptation to show off your vocabulary. The Will Self stuff doesn’t cut it in the fast lane.

Finally, part of the bestseller mystique is that it is just a matter of “knocking out” a book. This idea brings the red mist to authors’ eyes. Nobody knocks out a book. Artists can sometimes work quickly because they already have great gifts and immense skill. If Mozart knocked out a symphony in a couple of weeks, it was because he was a genius and had been practising since he was six.

Please do not make the mistake of believing that because something reads easily, it was easy to write. By all means make a start this holiday - Graham Greene reckoned 200 words a day was enough for anybody, at which rate you’ll only need 500 days for the first draft.

* Celia Brayfield is the author of Bestseller: Secrets of Successful Writing, published by Fourth Estate, Pounds 7.99 and Harvest, published by Penguin, Pounds 7.99 * Next week: Brian Aldiss on writing science fiction * The Arvon Foundation runs highly-respected creative writing courses in centres in Devon, Yorkshire and Scotland. The first 10 readers to send a TES masthead together with their address to David Pease at The Arvon Foundation, Lumb Bank, Heptonstall, Hebden Bridge, West Yorkshire HX7 6DF will receive the new Arvon brochure in January and 20 per cent off the course of their choice.