Grab a pair of dumbbells and sit on a flat bench with the weight resting on your thighs, palms facing each other.
Lay back on the bench and extend your arms (palms still facing each other), holding the dumbbells above you. Use your thighs to “bump” the weight up if necessary.
In a semicircular motion and with a slight bend at the elbows, lower the dumbbells out to your sides.
You should feel your chest musculature elongating during the descent.
Don't lower farther than your standard range-of-motion or at/below your chest.
Return back to starting position, on the same path as the eccentric, as you squeeze your chest to initiate the concentric portion of the exercise.
Keep the semicircular path as you bring the DB's up.
*Tips*
The arms should remain slightly bent throughout the movement. The arms are a lever between the chest and the dumbbell.
The focus of this exercise should be on the stretching and contraction of the chest musculature and should be done at a slow pace.
Going too heavy on weight can ruin the stretch and defeat the purpose of the exercise.
It can also wreak havoc on your shoulders as well.