Sometimes inspiration comes to me and I'm fire with a moment I have to pin down on paper. Immediately. Those are the good days. Other days, it is strictly what my editor calls BIC: Butt In Chair. Sit down and write. Something. Anything. 90 minutes. It's like working out—you hate going to the gym but you loving having been to the gym. You just have to do it to keep that creative flow strong and flexible. Your creativity needs as much exercise as your physical body does.
I also take a lot of inspiration from normal situations. I'll be cooking in my kitchen but imagining I'm a character in a story. Or gardening outside with a whole scene going in my head. Basically my head never shuts off. I'm always asking myself, "How could I describe this?" or "How could I capture this?"