First, we need to agree on what we mean by “inspiration?” Most good metaphors are connected to the body. So, to draw air into your body is a (generally) non-conscious process that maps nicely onto the idea of something outside your consciousness appearing almost as though the idea came from outside you (or your conscious awareness)—perhaps some divine or supernatural process (like the Muses)—many creative people have commented upon their art as a process of discovery and how they opened themselves up to it.

Inspiration occurs much like a “teachable moment”— learning something truly new due to an unusual convergence of who you are, what you are experiencing at the moment, opportunity, context, and even physiological state. It depends on disposition (congenital tendencies to prioritize the influence of different senses) and experience (guides development of those tendencies).

The great artist, Delacroix was inspired by words of Shakespeare and Lord Byron, but nothing, he said, compared with the emotion caused by music (he liked Chopin).

OK, so all that said, I am personally inspired in different ways at different times, but most commonly by the process of reflection expressed in writing on a past personal or vicarious experience —first thoughts are of all their possible alternate causes and consequences. That is, thinking more deeply about something I’ve read (often facilitated by rereading it out loud), and music. Often inspiration is like a dream that can be very quickly forgotten, so the sooner I can write it down or sketch it, the better it reflects my experience. I have had some great ideas that are utterly lost to me because I failed to document them.