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.
A friend recently started wearing men's jackets. They were extremely delighted by the discovery of chest height pockets inside the jacket, which really are supremely good ideas. Perfect for phone, wallet, passport, etc. In general, well-designed men's clothing is fantastic for pockets - my formal pants have buttons for back pockets (safer for my wallet!) and smaller pockets nested inside both front pockets (one for keys, one for coins, now I don't have keys sitting next to my phone, my keys are more accessible, it's great).
It might be worth looking through men's jackets and pants for something that fits you and looks good, regardless of what "gender" of clothing you usually wear.
Be aware, though, that putting heavy things regularly in men's jacket pockets - especially the inside chest pockets - will tend, over time, to spoil the 'line' of the jacket and make it look much less smart.
(Some people may not care about that, but it's worth considering - see e.g this response to this post.)