Pick one focal length and use nothing else for thirty days. Not a zoom set to a fixed point — a prime. 28mm, 35mm, 50mm, whatever you already own or can borrow. The constraint is the project.

Zooms make you lazy. When you can change focal length, you change it instead of moving. A prime forces you to use your feet. You learn what 35mm sees. You stop thinking about focal length and start thinking about everything else.