Think back to a time when you felt inspired. Maybe you had a great idea that you stopped everything to scribble down on the back of an envelope. Or maybe it was more general than that; maybe something you experienced just moved you to want to create something.
Ask yourself: What was it that brought that on? Was it natural beauty while you were on vacation? Was it watching a documentary about a favorite artist? Was it listening to a piece of music that you love?
When things go especially well, ask yourself: why did that go so well, and how might I create a similar atmosphere for future sessions? Sometimes what worked once works again. And again. And again, even.