sewing with a needle and thread. nothing complicated, the bare minimum is useful in a lot of ways.

i keep a small kit in my car because my pants waistlines keep shrinking mysteriously and i'm starting to randomly lose buttons and getting blowouts in the crotch. [likely due to far-reaching, nefarious, conspiracies and not b/c of the other kit in my car that's full of snacks].

what used to be my crippling, irrational fear of inadvertently exposing myself at like a job interview or in an uber with a cute driver, is now an easy fix i can do in a minute AND it's certain to make an impression.

old winter jackets with a lot of zippered pockets are especially great practice. try unstitching and removing a few of the pockets, then add them to other jackets or whatever you can think of.