Things that are unsexy but I can actually verify as having been useful more than once:

In wallet, folded up tissue. For sudden attack of sniffles (especially on public transport), small cuts, emergency toilet paper.

In bag I carry every day: small pack of tissues, multitool, tiny torch, ibuprofin, pad and pencil, USB charging cable for phone, plastic spork, wet wipe thing from KFC (why do they always shovel multiples of those things in with my order ?).