I wear 2 pairs of sox, and avoid walking on hard packed ground with my feet pointing strait down the hill. Side hill, and traverse, and keep your sox pulled up tight on your feet. Also some insoles can help with the proper fit of a pair of boots in rugged country. If your getting blisters from ''hiking boots'' you either live in a flat part of the country, or work in an office, or just plain have the wrong fit on your boots. Not bashing on you at all, but 20 miles is barely starting to ''break in'' a pair of boots. 2-3 weeks of constant wear, wet and dry will be closer to broke in.
Kinda like breakin in a new custom saddle, its gonna hurt, but when its done there isnt anything more comfy. As stated in an earlier post, turning your blisters into callouses is best and most painfull. We always fill up our new leather boots in the bathtub and leave them over night, then put them on the next day, and walk them dry to break them in. Do that a couple times, and your leather boots will be formed to your blistered, but eventually calloused feet. Grease the snot out of em and keep em that way and youll be fine.