You've certainly done this exercise before, but there are plenty of ways to shake up the set/rep scheme. Try this: Place three 5-lb plates on each side of the bar, hands at shoulder-width, and perform 20 reps. That’s one set. Then take off one plate from each side. Perform 30 reps. Unload another plate from each side and do 40 reps. Finally, remove the last set of plates, and do 50 reps with just the empty bar.