A very blister prone person here. Let me give you a miracle tip. Buy Body Glide (you can get it at most bicycle stores, runners stores, on the internet, sometimes at Dick's sporting goods stores, and occasionally at other sporting goods stores). Put it all over your feet in the morning before you put your shoes on and hit the parks (you never know where your shoes might rub at DL- I've gotten blisters on the top of my toes there before). Chances are you may never get a blister again. Before I learned about Body Glide on these boards I got blisters on every WDW/DL trip. I started using body glide on our 2008 trip, and I have not had a blister at WDW or DL since! Not one! We are open to close park people too- we walk all day long.
I also used to get blisters every time I would get a pair of new shoes, until they were broke in. Now I use body glide every time I get a new pair of shoes, and again, no blisters!!!
Our whole family uses Body Glide on our WDW/DL trip- we each bring our own stick. Even DH, who normally isn't really blister prone uses it to be safe.