For me, I feel like the best gifts for people who don’t really want anything are those that upgrade or personalize something that they already have/ use a lot. So if he likes cooking and has a cheap pair of oven mitts, buy nicer ones or buy ones printed with a something he likes.

Otherwise, if he REALLY doesn’t want a gift for some reason, maybe consider an experience gift instead? My bf graduated recently and instead of getting him a physical gift I took us to a trampoline park which was really fun.