When I was an Air Force pilot, many of us carried personal survival kits in our flight suit made from a plastic soap holder with duct tape around it. I don't recall what I put in mine.

My first aid kit is a pair of scissors. I figure I can make any sort of bandage I need from some article of clothing. I can make it germ free by boiling it, if needed. I don't bring a knife, so I never have to treat knife wounds.

If I were the type to get blisters, I would learn about treating them and keep the right things with me.