Repositories are awesome, and we should have more of them.
I recently completed BJ Fogg's Tiny Habits, and it's a pretty lightweight way to install new habits (recommended). However, I realized I could use a better repository of useful habits.
So, please use this thread to suggest habits that you've found useful. Bonus points for evidence/anecdata of usefulness.
Obviously, 1 habit per comment makes upvotes a clearer signal of collective approval.
Coursera is excellent for it - any Coursera courses have playback speed options. I usually go x1.5 for sciences and x2 for humanities(since humanities tend to have lower information density), but you can vary that a little depending on the prof's talking speed and the content of the lecture you're watching.
I know Coursera isn't the only source of informational video, but it's a good starting point.