When I was in college, I had the pleasure of taking a couple math classes taught by Mike Starbird. One of the things he told us about problem solving was this: when you’re stuck, draw a picture. Good advice, though hardly original. But then he said something else: If you’re still stuck, draw a bigger picture.
When you draw small, you think small. It’s surprising how much your thinking opens up when you draw a bigger picture. You can draw some little diagram and think “that didn’t help.” But when you take that same unhelpful diagram and make it much larger, it may be just what you need.