It just takes time to get the feel of how to hold and operate the buffer in different positions. On vertical surfaces don't push the polisher to the panel let the weight of the polisher rest on your trigger hand than float it up down left right.
The first rule when using a rotary, is to never stop moving the polisher when it's spining. I move the buffer at about four inches per second. That will vary with different speeds. If you speed up the polisher you also need to speed up, remember todays automotive finishes don't like heat.
Hope this helps.
