When my kids were in college, I would buy gift cards to local restaurants that they liked. Now that they are older, I’ll do DoorDash, Safeway, Costco, etc. I avoid Amazon because they seem to get a lot of Amazon cards from other people.
I’ll go to Five Below, the Dollar Store (when it was open), Aldi, etc. and find something cheap to attach the gift card to. I’ve been surprised that, on occasion, they sometimes used the cheap items (ex. calendar, candle, food item).