If I had a magic flying broom, I would use it to do parcel delivery in a small, idyllic city somewhere.
Has someone been watching Kikis Delivery Service?
May find digs in a bakery.
Various superpowers: Generating free energy.
Psychological horror about the government taking all supers and putting them all in one giant box so they can use their powers to boil water. They all think it’s for the greater good. Plot twist is that it’s actually someone’s basement
You should read Fire Punch.
Superman’s X-ray vision would be awfully useful for surgery. For that matter, X-ray vision plus precise heat-rays could maybe be tuned to vaporize tumors in-situ.
Shape-shifting to get unlimited free samples
Any kind of mechanical work would be easy if you can selectively phase through matter, way better than evading assailants or sneaking around.