SETUP: Take an overhand-grip on a barbell, hands placed at about shoulder-width distance.
START: Most people move their shoulders round in a circle motion. This is wrong. Instead, pull the bar up & back.
FINISH: Add a slight pause to the top of the rep, and feel the stretch at the bottom of the rep.
TIP: Pick a spot in front of you and stare at it. Resist the urge to raise and lower your head on each rep, this places the neck under unnecessary stress.