Read and win the 1v1. Start the ready position on the line, time the rush to narrow the angle as the attacker takes his touch, stay big, and block the shot before smothering the rebound.
A server slides a through ball for an attacker to run onto in a 1v1. The keeper starts set on the line, reads the trigger (the attacker's heavy touch), and rushes out to narrow the angle. Stay big, make the block, and smother the rebound. Do not dive early or go to ground too soon. Rotate server, attacker, and keeper, and vary the angle of the through ball.
Fork it into your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block.