Other climbing skin trimmers do work, but this stellar example of industrial design takes all. Gecko cutter (GUTT, Gecko Ultimate Trim Tool) has replaceable blade; flexible tangs hold the edge of the skin down while you cut; even looks nice in your Audi center console.
Gecko climbing skin cutter can be configured for right or left handers. Blade safely hidden to avoid flaying yourself. I got as good or better skin trims than with other methods, had a bit of trouble keeping the cut as far back from the edge as possible since the trim action is somewhat hidden from sight. A bit of practice should make that a non-issue. One has to wonder if this is some sort of adaptation of an upholstery or textile tool. Whatever, it works. Wildsnow.com recommended tool. Christmas gift for the skier who has it all?
Gecko climbing skins website, North America.