This is a tough one. My characters inspire me, the what-if's that are clamoring at my brain inspire me, and the fact that I'm happiest when I'm writing inspires me. That doesn't mean I'm always in forward motion. Since I can't seem to write anything but complicated, I sometimes get tangled up in my own thoughts, and I need to take a break to smooth out the wrinkles in my plot. Also, I need dead silence. No music, no talking, no noise (except my puppy's snoring). So the creative conditions have to be right for inspiration to occur.