Full swing · Changes the swing

Divot line

Setup in 3D
3D view
Setup from above
From above

Mark a line across the turf. Make swings so the divot starts on or just in front of the line, first without a ball, then with the ball on the line.

Trains
Fat, Thin, Top, Low point
Dose (suggestion)
10 swings without a ball, then 20 balls
Count
Divots starting on or ahead of the line, out of N
Stop signal
Stop: pain 3 out of 10 or more, pain spreading into an arm or leg, numbness, or more pain the next morning.
Source
HackMotion: How to stop hitting fat shots