What's one small dev habit that made a big difference for you?

Lately I've been trying to write down what I actually did at the end of each coding session, even if it's just one line. It sounds tiny, but it's saved me so much time when I come back to a project a few days later and have no idea where I left off.

Curious what small habits other people here swear by. Could be anything from naming conventions to how you organize branches or take breaks. I'm always looking for low-effort things that quietly make things better.