Set an incline bench at 45 degrees.
Grab a pair of dumbbells, and approach the bench with your chest toward the angled pad, then lean onto it. Plant your feet firmly on the floor, and let your arms hang straight down, palms facing each other. This is the starting position.
Squeeze your shoulder blades together and drive your elbows toward the ceiling, bringing the dumbbells to your ribcage.
Slowly reverse the move, and repeat for reps.