I preempt blisters by putting larger bandaids on potential hotspots. For me, that's the heel. I also tie my hiking boots tight, which prevents the foot from sliding inside the boot. I also use plastic shoe liners covered with foam. The hard plastic supports my arch, which is my problem area. I tried 5 types of foot insoles 1 winter before I found the right one. I have been using that particular pair of insoles for 10+ years.