STEP 1: Film It
Use a phone, tablet or other video recording device and film 3-5 swings from a side view standing approximately 10 feet away from the hitter. You should be able to see the hitter's feet and bat throughout the entire swing.
(this should be about a :30 sec video clip)
Hitting a moving ball is best, but not necessary.
Attempt to get the entire body and bat in the video.
Hitting with a homeplate in the shot is recommended.
Keep the camera as steady as possible. A tripod or other mount is ideal to use when filming.
Hold the camera as shown in the picture (landscape or widescreen).