Suffered horribly on past trips, to the point where I could barely walk. DH said that he wouldn't take me back to WDW until I found a solution... and here it is!
A great runner's shoe store here in Indy made these suggestions. First, use Vaseline on your feet and between your toes. This will help ease friction. It works!
Second, I only wear Cool Max sock, available at running stores. They come in light, medium and heavy. I wear the light ones. They don't have a seam that rubs.
Third, get great shoes for your feet. I have to wear Saucony's. I have little (size six) feet, but they are wide.
I also carry the blister blocks and pre-cut moleskin in my day pack. But have not needed either.
Have had two blister-free, blissful trips since. And leaving in 31 days again!
Good luck