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.
For people who prefer purses (I like them more stylistically, and also for the increased carrying capacity), I have found that using a smaller, more structured one with lots of pockets/compartments works well for solving this problem. Things I use often (like keys, cards, phone) are in specific easy to reach pockets, and I can easily find them and replace them by feel.
Nested bags work well too. I have one of those huge waterproof messenger bags & it is like a bottomless pit if you don't organize it somehow.