Thoughts for Scouts on blisters:
Understand shear forces. (Grab some skin on your hand and move it back and forth. It is likely not shallow surface friction causing your blister).
Your boot pulls back and forth against your sock, which pulls back and forth against your skin and underlying tissue, which pulls back and forth against your bones and ligaments and tendons.
Shoes should have enough space around the toes so that your toes are not scrunched up (you need a big toe box). The inside of your shoe and edge of your insoles should not have large seams rubbing against your foot.
Your socks should not be worn thin, and should not have very large seams that rub against you.
Trim your toenails. You can also file down the edge of your toenails so they don't catch on your socks
Fix hotspots on the hike when they occur before they become blisters (tape the hotspot).
You have a blister? You can tape or pad it. However, if it makes walking painful then it is ok to lance and drain it with a sterilized needle, then treat it like a small open wound with your personal first aid kit.
A blister under a callus can be painful. This is probably more fore adult leaders than Scouts, as Scouts don't tend to have as many calluses. Either soften/file down a callus beforehand, or pay attention to that spot to avoid blisters.
During long breaks dry out your boots and socks. Change to a dry pair of socks if your socks are damp from perspiration.