Read and Call
Why this drill
The difference between 3.5 and 4.0 kitchen play is rarely the hands — it is the read. Calling every incoming ball out loud forces the attack-or-reset decision into the open, where it can be trained.
Setup
Both players at their non-volley-zone lines, straight ahead. The feeder has balls in reach.
The drill
The feeder dinks deliberately varied balls — some tight and low, some a touch high, some at the body. The receiver calls each ball in the air — "reset" or "attack" — and then does exactly what they called: resets go softly to the kitchen, attacks go firmly at the feeder's paddle side. The feeder grades the calls, not just the execution: a good attack on a ball that should have been reset counts as a miss. Sets of ten, then swap roles. Track calls and execution separately — most players discover their calls are wrong more often than their hands.
One thought to take on court
Decide at the peak of the ball's arc — if you're deciding at contact, you already guessed.