Overhead Cable Extension
Set the pulley at roughly head height. Using your front foot to stabilise, stand in front of the cable machine, and lean forward to about 45 degrees - holding the handle out in front of you, at the same angle as your body. Start easing the handles back behind your head, slowly with control. Extend the arm back out in front of you, again, keeping control. Don't completely lock out at the top of the movement - keep the muscle under tension the whole time.