SETUP: Use a 45* angled bench. Lean into the bench, your legs should be straight. Take a neutral-grip on the dumbbells (palms facing in) and pin your shoulders back.
LIFT: Move the weights by pulling your elbows out and squeezing the muscles across your upper back.
TIP: Make sure the weights are moving out, like a dumbbell flye motion, as opposed to BACK, like a skiing motion.