To use a downscreen, start under the basket, get low, take a hard step with an arm bar into your defender to take him away and create some space, come off the screen shoulder to shoulder. The three shot options are
a) pop (shown) - straight then take one step towards the passer to create a better angle and cut off the defender recovering
b) fade (to the corner) - when the defender goes over the top of the screen, take one hard step past the screen with the inside foot, then two steps back, get behind the ball with a 1-2 step into the pass
c) curl - tight to the basket if the defender trails.
After each shot take your man down from the wing. Do one rep of each on both sides for six shots. Rotate passer to screener to cutter to screener to passer (e.g., clockwise).