Body Glide -- which one?

The anti-chafe Body Glide that looks like a deodorant stick. I rub it on my feet in morning (all over foot - top, bottom & sides) before putting on shoes or sandals. Works great. No blisters ever, even when not wearing socks.

Or just use a stick deodorant-antiperspirant. A cross country coach showed me the trick years ago. When your feet sweat your socks get wet. If they're cotton socks, they lose their cushion and you start to get friction that leads to blisters. Using antiperspirant on your feet keeps them dry and allows your socks to keep their cushion and reduce friction.

This one is fine:

http://www.rei.com/product/745879/bodyglide-anti-chafe-formula-13-oz

When I bought mine 8 years ago there was only one kind. Now there is one "for her" and others for saddle/chamois friction for cyclists, etc. I have good results with the basic one, use it on top of my toes and between them as well as on the heels.

I always carry a Band Aid Friction Block stick in case my shoes start to rub. I initially got it when breaking in a new pair of running shoes, but I found it's great for everyday use, too. It's super cheap and tiny, which makes it easy to always have in your bag.