I keep a guitar around while writing and will improvise music. I do this for several reasons, such as that it's fun, and sometimes it helps me with the meter.
I invented animals and birds - I had about two dozen. After working on them for six months, I sat down and just for fun wrote two dozen poems to accompany the drawings. It was for no one to every see, but a friend sent me in to an editor.
My reading is extremely eclectic. Lately I've been teaching myself computer graphics, so I'm reading a lot about that. I read books of trivia, of facts.
After I'd produced about two dozen pen and ink drawings, one evening I decided that they needed poems to accompany them. I still have no idea where that notion came from, but it took me about two hours to produce verses for these creatures.
Poetry seems to sink into us the way prose doesn't. I can still quote verses I learned when I was very young, but I have trouble remembering one line of a novel I just finished reading.
I'm working now on a collection of Shakespearean sonnets, about 100 of them, that I may publish if anyone's interested. My take on life is a little different from the bard's.