It's one of the standard questions writers get asked: Where do you get your ideas from? The short answer is something like, Ideas-R-Us, where you can get a boxed set for £9.99 and the deluxe version (bestseller guaranteed) for only £19.99. The reality is that ideas are all around us, whether from something we hear from friends, or see on television or read in the papers or just from observation of daily life. Finding ideas really isn't a problem. Finding a good idea is another matter.
A good idea is one that matters to you. That's why it's no good telling me all about your amazing idea and suggesting I might like to write it up. The idea is amazing to you, so you should write it. It's not MY amazing idea, so I'm not going to spend the best part of a year slaving away - writing is hard enough when it matters. The next thing to look for is scope. When you think of your idea, lots of possible directions should come into your head. Some writers use spider diagrams for this stage - you know, those ones where you start with a word in the centre and radiate ideas, joining them with lines so the end result is a page of words all linked like a spider's web.
I prefer to play What If. What if this happened? How would I react? What might happen next? What would make it really tough? What if that happened? And so on. With A Single to Rome, I started with What if you thought you were going to marry someone, and then they dumped you? How would you feel? What would you do? Would you want revenge? (By the way, that's why my working title was 38 Bonks.) I knew I wanted to send Natalie to Rome because I'd been a student there and fancied writing about it, so why was she going? To escape, fine, but who was she going to stay with? How would she meet them? What if they had their own problems?
In answering those questions I was able to start writing, and in the process of writing the novel, ditch some of the original questions and ask new, more interesting ones (which is why it didn't end up being called 38 Bonks, although that stayed as the working title because it makes me laugh). Good ideas inspire good questions. Good questions inspire good answers. Good answers mean - I hope - good novels. It's either that, or this year for Christmas I'm asking for the deluxe idea set.