Ask HN: What are your favorite developer-efficiency tips?

I recently started integrating tmux and vim into my workflows. Obviously, it was a huge efficiency booster. What are some other tools (custom built or off-the-shelf), hotkeys, workflows that were game-changing for you as a dev? I'm interested in hearing about anything and everything (stuff from ctrl+l to clear the terminal to little-known git commands to larger-scale strategies like CI/CD)