Blisters First Aid

The signs of, and treament for, Blisters

Anythgin that rubs your skin too much repeatedly can cause a blister, a skin iritaion that

Use Moleskin (or, in a in pinch, duct tape). This thin layer of spongy cotton foam with a sticky adhesive on one side acts as a cushion to keep your shoe/sock from rubbing your skin.
If it just a hospot, cut a piece of Moleskin large enough to fit the hotspot (plus a litle bit extra on all sides; maybe 3-5mm) and apply it directly to the skin.
If it's a blister, the prep is a bit trickier. Cut the Molekskin about half an in inch larger than the blister on all sides. Then cut out of the center a hoel large enough to contain the blister.
Round off the corners. Use your knife/multitool's scissors to trim the corners of the Moleskin patch into nice quarter-circles rather than sharp right angles. If you leave the patch rectangular, those corners tend to catch on your sock and the action of walking starts to roll the corner down and peel off the Moleskin.