I don't have a steady rhythm where I figure out my characters first or my plot first, but there's always that idea that pops into my head that makes my eyes widen and my heart race. The thing I start daydreaming about to try to see how I can build upon it. Usually it's a small clip I play in my head. It's the beginning excitement of a new journey through the sometimes overwhelming process of a new book.
It's important to capture that idea when you have it. Writing it down is great, but I don't always do that when I get the new shiny idea. Sometimes the idea doesn't feel ready enough for that. Like I mentioned in my post, The Slow Simmer, I tend to think things through first over and over. Of course, there are the exceptions when I don't think the idea is shiny enough to hold my attention like that for a manuscript, but good enough to fit into something else.
Recently, I had an idea for either an urban fantasy or paranormal romance, I'm not sure which it is yet, and I went into The Sims 3 and created a couple of characters to get a better feel for them. It helped me to solidify the people I saw in my head. Now that I know those things, I'll be able to write them down during character creation. It helped to capture the idea for me.
Now that I've done that, I'm free to delve deeper now that I've pinpointed the main aspects of the idea to further build upon. Then that allows me to figure out what in the world was going on between the characters! *grins*
Anyways, what ways do you have for capturing your ideas? How do they come to you? As characters, plot, or random scenes?