One of the best treatment, and pretreatment for blisters is mole skin. It comes in two sheets approximately 4 x 6. Super sticky on one side and very soft, felt like material on the other. You cut the moleskin to fit your need. My DS has used it in his cleats for years, either on his foot or adhered to the boot. It does not come off easily, so even when sweating, it will stay on the foot. I myself use it on every vacation where I walk -- just trim a piece off, stick to offensive area -- no more rubbing. I have even used it when a piece of clothing was rubbing my DD's waist and we could not change the shorts while touring. Very versatile. Easy to pop into an envelope and mail.
Purchase it near the Scholls insert foot products. Well worth the price (about $3 per pkg, 2 sheets to a pkg) and even our local grocery carries it. Be sure your DS or DD has scissors to trim. I packed all of this in both my DS athletic bag and his sea bag.
As far as the glue, tape, etc., the other mids comments are right. The more supplies to basically duct tape, staple, or pin everything in place, roll lint off anything, trim nubs off of blankets, glue down, dust, clean, etc., is valuable to them. That was another bag of supplies that went with my DS. I sent several bags of handi wipes that are sold in flat pkgs, disposable dust rags with the cleaner, tide pens, etc. I know these things will come in handy before inspection and help them to keep their room clean. These will be a permanent part of many care packages that go out this year!
I hope this helps!
