I only wear Saucony tennis shoes... they are great for wide feet. Also, Dr. Scholl's makes a blister blocker product. Much like a band-aid, but seems to work well.
I also wear the cool max socks, but I like the ultra-thin ones. They don't get bunched up in my hot shoes.
I had a podiatrist recommend putting Vaseline between my toes before putting on my socks. My toes rub each other and cause blisters between the toes.
Haven't had a blister in years at WDW... and I used to get ones the size of golf balls!