Like most things, you’ll need to practice this to get the hang of this slick-looking method.
People trying this method will sometimes overlook the obvious: You don’t hook the end of the tape measure over the end of the drywall, as you would when measuring. Instead, you place the tape’s hook where you’ll be making the cut. Put the tip of the knife blade against the hook and pinch the blade there with your thumb. Your other hand goes at the end of the drywall, pinching the appropriate-length measurement on the tape.
From there you move both hands at the same time, drawing the knife and tape down the drywall with consistent downward pressure. Crack off the piece of drywall and cut the paper on the other side to release it. If a guy like me with two left thumbs can do this, you can too.
Author: Roy Berendsohn
Source: Popular Mechanics US