I'll post this because it hasn't been mentioned yet. Buy your footwear larger than you think you need.
I run in size 10.5 running shoes. I typically hike in size 11.5 trail runners, in a wide width, and just use the insoles that come with them.
I used to always get blisters when hiking more than a few hours. Getting footwear a bit large completely cured me. I don't think I have had a single blister since I made this switch, and I would never have thought to do it if I didn't see the suggestion on this site a few years ago.