01
Step one: fix the capture conditions
Decide camera position, distance, height and the club or bat used before recording anything. A golfer might film from down the line at hip height with a seven iron, five swings per session. Write the setup into the profile so later clips match it. Without that, a change in angle looks like a change in swing. Keep the first capture short, because a few consistent clips teach more than a long unstructured recording, and players are likelier to repeat a routine that takes minutes.
02
Step two: choose a few measurable markers
Pick three or four observations to track rather than everything visible. For the golfer, these could be tempo between backswing and downswing, clubface angle at the top, and head position at impact. Mark them on a frame or note them by eye if no sensor is present. A baseline is the average of the first several sessions, not a single best swing. Label each marker in plain language so a player understands what moved and can describe it back to a coach.
03
Step three: compare, then change one thing
After each session, place the new clips beside the baseline and note which markers shifted. Suppose the golfer's tempo is steady but the clubface opens at the top. Assign one drill aimed at that marker and leave the rest alone until the next review. Record the drill and the date in the profile. Over several sessions, the history shows whether the change held, drifted back or created a new issue, giving the player and any coach a shared, specific reference.