While training for my trip to Corsica I have had a few problems with blisters and sore feet.
I changed my boots and got new socks .
A few people recommended the Gehwol foot creams from backpacking light.
I was reluctant to buy these as they were so expensive,but I decided to treat myself and have not regretted it one little bit.
Not only do they smell real nice but they feel real nice too and leave no greasy after effect.
I especially like the refreshing foot balm , and put that on during the day, usually when I change my socks. Its cool and refreshing and feels great.