I think the most frequently asked question that an author gets is "Where do you get your ideas?" The first time I heard Brandon Sanderson speak, he told us his theory. I kind of love it, so I'm going to share it with you guys.
He said that every time he comes across something that he thinks is cool (inspired by a movie, a character, a book-- whatever), he writes it down, and sends it into his brain to bounce around.
Notice he doesn't just use the idea as soon as he gets it. That first idea is likely to have been done a million times already. He sticks it in his brain, and lets it bounce around with all of the other ideas in there. Any one of those ideas by itself could've been okay, but the magic comes when two ideas stick together. Usually when they stick, they are things that are unique. Different. They have their own sets of conflicts inherent to just plain being together.
When they stick, that's when you have an idea that will allow your own special twist on things, that will make it different from everything else out there.
He gave the example of his book MISTBORN. (If you haven't read it, ohmygosh READ IT! Seriously. It's fabulous. Even if you don't love fantasy, you'll still be able to appreciate the unfathomable amount of thought that went into it.) Anyway, Brandon watched a heist movie. I can't even remember which one, but after he watched it, he thought about how much he really loved heist movies, and stuck that idea in his brain to bounce around. He already had another thought in his head-- the magic system that he used for a previous book that hadn't worked out. He didn't love the main character or the setting, but the magic system was awesome. (And trust me when I say he wasn't wrong.) Those two ideas stuck, and he wrote a heist novel, where each person in the group had a different magical specialty.
Two common ideas--- a heist and a magic system where each person with a magical ability only has one ability--- that were unique and different and interesting when they were put together.
I don't know about you, but the idea of ideas bouncing around in my head not only sounds pretty effective, but makes it all sound SO MUCH MORE FUN.
I write action / adventure books for middle grade readers, and I'm represented by Sara Crowe of Pippin Properties. I have two books released-- SKY JUMPERS and THE FORBIDDEN FLATS (both action / adventure, for ages 8 and up, with Random House Children's Books). I love happy kids even more than I love cookies, I make lists as often as I eat lunch, and I love having every light in the house on almost as much as I love writing.