I sincerely wish you luck with this one. I am lucky when it comes to blisters on the feet, I don't really get them unless there is something abrasive in my shoe.

I'm in the BZH camp of making sure the fit is right "now". I have had to ditch a few pairs of footwear this year after aging feet outgrew them. They began to rub my toes raw resulting in nasty soars on the tips of my toes. I do have big problems with the cold that also contributed to this but I think in many case that friction and moisture lend greatly to any foot problems. I know I get wicked blisters on my hands when I rake leaves without gloves and that is purely friction related.

I would approach it more or less scientifically changing one variable at a time to see what actually eliminates the problem, then you might be able to apply it to all your footwear.

Hoping for a blister free future, jimmyb