HOW: Start by facing the wall/anchor and grab two separate bands, cross the bands in front of you and pull them towards your hips. Keep tension in the bands the whole time by drawing your shoulder blades and hands back. Slowly raise your arms in front of you like doing a snow angel.
FEEL: You should feel all the muscles in the back of your shoulder blades working.
COMPENSATION: Do not let your back arch of loose tension on the band. Keep your thumbs either pointed up or backwards the entire time.