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.
Geometry governs the 1v1 and it cuts both ways. Every yard a keeper advances removes a slice of goal the striker can see, so a keeper on his line faces a wide target and one at the penalty spot faces almost none. Every one of those yards also increases the amount of space behind him, which is what makes the chip available. The whole skill is choosing where on that trade-off to stand, and when to move.
The timing cue is the striker's touch, and specifically the moment his head goes down to take it. That is the only window in which a keeper can cover ground unseen. Advancing while the striker's head is up simply shows him the picture and lets him adjust, which usually means a shot into the space the keeper has just left.
Out too early and the chip is on. Out too late and the angle was never narrowed, so the striker picks his corner from a wide target. Getting this wrong in either direction looks the same from the sideline, a goal conceded, but the corrections are opposite, and a coach who cannot tell which error occurred will coach the wrong thing.
Staying tall is what converts good positioning into a save. A keeper who arrives well positioned and then immediately goes to ground has handed the striker the whole space above him. The longer he stays up, the longer the striker has to keep deciding, and pressure is what forces the mistake.
Save it to your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block. Or start from a blank pitch and build your own.