I saw someone mentioned moleskin for blisters. Just a bit of info to provide to prevent those blisters. Each morning, after the shower and before dressing, spray your feet with antiperspirant/deodorant. Any kind will do---a cheap $1 can of Suave works fine. Spray in between toes, soles, sides, etc. This will prevent your feet from sweating which results in friction and blisters. If you rest in the afternoon, reapply the deo before going back out. We could have potentially not needed to reapply, but why take chances?
My spouse and I ended up with over a dozen blisters on our first trip. WDW does not have any real relief aids for feet. After this tip, not one blister have we had since. Hope it works well for everyone.