So I’m writing again. I have an idea for a novel – in fact, an idea I’ve had knocking around for several months. It came while I was idly musing on the multiverse in The Last Man on Earth Club; I recalled Nick Bostrom’s Simulation Argument, with its hypothesis of ancestor-simulations created by advanced races, which might spawn further simulated worlds within worlds that were already simulated, something that could continue with levels of universe-nesting only limited by the processing power in the original universe.

Well, I thought to myself, a multiverse based on that idea would be an interesting setting and rather different to the usual story excuses we have for multiverses (quantums! branes! probabilities!), which are usually based on highly speculative physics. I wouldn’t be surprised if someone has used this before, but still, if I can come up with the right characters and worlds and story it might be useful...

Which is to say, the idea is worth very little by itself. Ideas are only seeds that need to be watered with research, experience, hard work and more ideas. At this stage, I had no characters, no actual setting beyond the idea of a simulated multiverse, and no idea what the story was actually going to be about. All these things did eventually come after a lot of brainstorming, but the idea wasn’t enough on its own. In fact, the original idea might even end up being thrown out or just de-emphasised because some of the stuff I’ve created since then seems more interesting.

And yet without that original idea, I’d be nowhere.

So let’s take a look at ideas, and how to get them...

We’ve all been asked where our ideas come from, usually by friends, family and readers who can’t imagine how they could even start coming up with something like your finished book, and fail to realise how small and simple the first step can be. And half the time, we don’t even know where to look for ideas, or how to tell when we’ve found one that’s worth developing. And of course they can come from anywhere. Something that happened to you as a child. Something you saw out of the corner of your eye on the bus. Something you read in a newspaper. A shocking story about your family told over dinner by an elderly relative with Alzheimers who forgot they’d sworn never to mention it.

(oh wait... that last one is an idea in and of itself. Maybe not a great one, but certainly a seed from which a story could grow. See? You can get ideas while writing blog posts about trying to come up with ideas...)

Sometimes the universe just dumps an idea in your lap. The (very) recent death of a friend of the British Prime Minister in the middle of the Glastonbury Festival is of course a tragedy, but every writer of thrillers and mysteries in the UK has probably read the news this morning and been unable to avoid thinking how that could be the starting point for a story - after all, it's not a million miles away from the inciting incident of State of Play, an excellent TV series from a few years ago. Or maybe there's something that happened to you in your life that gets you started on a story. Or maybe someone tells you about a funny story from their life. Maybe you just stumble across something on he internet. But most of the time, you don't get that lucky. You have to go looking for ideas rather than waiting for them to come to you.

Of course, looking for an idea is usually the moment they dry up, because ideas are rarely the product of the more rational parts of your mind. They come more from the free-associating, pattern-recognising bits of your brain that usually go to work in your idler moments. You can call it daydreaming, if you like; when you’re not distracted by sensory input, or are doing something so routine that your attention can drift. Driving a car on the motorway, maybe. Public transport, for certain. Brainstorming works as well, because you’re deliberately not exercising judgement; just listing all kinds of crazy stuff that might possibly be of use, regardless of how much it makes sense. Somewhere in that list might be something unexpected and useful (which is what happened a few paragraphs ago as I was trying to come up with a list of potential places you could spot ideas).

Getting an idea is helped enormously by giving your brain something to free-associate with; information and knowledge it can recognise patterns within. So keep on reading, and not just within your own genre. Keep up with the news. Study history. Watch documentaries. The more you know, the more connections you’ll make when ideas come along. And pay attention to what people say: the smallest phrase overheard in a bar can lead to an idea. I got a short film script from hearing someone say he was playing eyeball tennis with someone he fancied; his phrase, but the visual metaphor immediately set my brain off thinking how you could actually show that happen, and make it funny.

Inspiration can go horribly wrong, of course. Especially when you’re young, and every idea you encounter seems new. The worst ideas I’ve ever seen are usually ones which are essentially rip-offs committed because the writer was bowled over by a film or a book and mistook that sense of amazement for an idea of their own. The major turning point of Fight Club, for example, inspired more than one script I had to read through back when I was helping people learn to make films, and they were all tedious, tedious, tedious.

So it’s important to exercise some judgement on your ideas when they come. That’s where the rational part of the brain wakes up and gets to do some work as well. So here’s some quick things to consider about any given idea:

• Are you interested in this? You probably are since you realised this was an idea in the first place. But you might still get ideas that don’t quite fit the kind of thing you write. The idea about the elderly relative spilling family secrets that hit me a few paragraphs ago is probably not one I’ll use, because I write science fiction. The idea was interesting as an individual scene, but I can’t see it going anywhere that keeps me interested. And if I’m not interested, I can’t expect anyone else to be. Maybe it'll be useful one day, but not right now. So make a note of it, and move on...

• Has it been done before? Well, pretty much everything has been done before, so you can’t rule out something just because someone else got there first. It depends on how specific your idea is; a multiverse based on Nick Bostrom’s simulation argument is very vague and will likely result in something different to other attempts at the idea. If, on the other hand, your idea is about an American adventurer who has his or her adventures while operating as an archaeologist, you’re likely to be compared to Indiana Jones no matter what you do. You’ll need to find a new angle that makes your idea sufficiently different, or make a note of the idea and move on...

• Can it be marketed? Okay, so you might think it’s a bit early to be considering this, but even so, you should be keeping an eye out for it. Some ideas just write the blurb all by themselves. The Last Man on Earth Club was one of these; the original idea is pretty much what’s in the description on Amazon, and people tend to comment that it’s the concept that motivated them to buy the book. You don’t need a marketable idea as your starting point, but if you find one – jump on it! (and bear in mind that you still have a hell of a lot of work to do)

• The most important thing of all: can it be turned into a story? If it’s just a setting, can characters be inserted who will do interesting things? If it’s a character, can you imagine interesting things happening to them? If it’s something else, can it be developed into something more than a static situation or scene? Of course, in order to figure this out, you need to know what a story is, so here’s one very quick and dirty definition: you get your characters up a tree; you throw rocks at them; you get them down again. It doesn’t have to be an adventure. But events need to happen, and characters need to go through them. If you can’t see how a story could happen... make a note of it, and move on.

And then once you’ve got an idea that makes you interested, that isn't completely unoriginal, and that you can turn into a story, and that can be marketed (maybe), all you’ve got to do is write the damn thing. Which is where it gets a lot harder. More on that some other time...