A player stands in the lane without a basketball, facing the baseline
A coach has a basketball around the free throw line area
Without notification, the coach throws the ball against the backboard
The player in the lane has to react to the ball and rebound it
After grabbing the rebound, they can work on a variety of finishes:
Catch, land, power lay-up
Catch and tip-in while in the air
Catch, land, shot fake finish
Etc.
Work on timing and reaction
Get "clean finishes"
Rebound the ball with two hands whenever possible