Leg warmers may have been invented by the aerobics crowd but they sure do work. I use them all the time, alpine climbing in Patagonia, rock climbing with Marko the other day in the freezing temps or just to add warmth when ice climbing. The principle behind leg warmers is simple, send warm blood down to your feet and your feet will be warm.
I made my latest pair from an old pair of expedition weight long underware. I cut them just below the knee, then sewed in an elastic cuff. they are not tight but the elastic seems to not slide on my usual pair of base layer long undies. They provide insulation when post holing but have the advantage of not making my legs overheat. The best use I have found so far is for cold rock climbing days, they can be pulled down over your heel to keep your feet warm while climbing.
