1. Compression type Smart Wool Socks
2. Two Toms brand Sport Shield Liquid Roll On.
3. Insoles: Green Super Feet
I am still ruck'in these days (an old LC-1 pack frame with 40lbs of weight plates zip tied to it [I am certain I am quite a sight if anyone is up at 04:30 AM]), so I believe I know what I am talking about. Six to ten miles per day. I wish I had figured this all out while I was on active duty!
I have noted specific manufacturers, because, these are what have stood the test of time and miles for me, your mileage may vary. If you find a less expensive substitute that works, please share with the rest of the class.