Hold one side in an isometric contraction while the other arm moves through a dynamic (concentric and eccentric) movement. You then switch sides.
This simple modification not only helps you to create a new training stimulus, it also creates muscular overload by increasing the time under tension (TUT). By increasing TUT, you increase metabolic stress, a key mechanisms for growth.
If you're a bodybuilder and you've spent your weightlifting life doing sets of 8,10, 12, etc., doing singles will absolutely blow you up. A terrific idea and a terrific program that'll raise you head and shoulders above the competition.