Three things
Here are 3
Pick one. Each takes about as long as it says.
Teach a child something genuinely useful
Changing a tire, wiring a plug, making one good meal. Competence is a form of confidence that lasts.
An afternoonUnder $10A friend
Find the subscriptions someone forgot about
Most households pay for several things nobody uses. Finding them is an hour's work and a permanent saving.
An afternoonFreeA friend
Scan the box of photographs
Boxes of prints are one house fire or one house clearance from being gone. Scanning them takes an afternoon.
An afternoonFreeA friend