Hold the tool shaft steady as you crank and push down on the handle. You'll feel the cable snake its way up and through the trap.
Continue cranking until you've dispensed the entire cable—about 3 feet. Retrieve the cable by simultaneously cranking and pulling up.
Flush the toilet to clear out the drainpipe. If it's still a little sluggish, run the auger through the trap twice more: once up the left side of the trap, then again up the right side. This three-pronged attack will clear any matter clinging to the sides of the trap.