You probably won't be able to pull this off with one square (thus greatly disappointing Sheryl Crow) but this technique should reduce the amount of toilet paper you need -- and make you cleaner as well.

Basically -- and this is really sad because I'm just realizing this at twenty-seven years old -- you just put a couple of squares between your index and thumb and pinch your butthole with them (from the front). Whereas a "wiping" motion will simply spread the feece out, creating more work, the pinch should suffice, unless you have caca all over your buttcheeks.

Over and out.