Half of it just comes in brust out of no where and it flows, the other half I capture an idea and consciously try to push the words out of me. What I think is important is to open yourself up to different things, and read or listen to varied quality stuff. All art is a rework of someone's idea, but with your twist, so I advice you to read and listen to the greats in each field. The more you open up yourself to different ideas from different places, the more you make it easier for your mind to come up with something.