1. Focusing a fixture from the ground, guessing at the pan, tilt, shutters, sharpness, etc., then running the electric back to trim. Make note about what you guessed wrongly, bring the electric back in and redo, repeat until satisfied. Also known as "yo-yo focusing" due to the movement of the batten. See the article at Lighting Angle Focus Solution | Mt. Vernon High School Performing Arts to possibly prevent some of the down and up trips of the batten. Or see the thread bounce focus aid with speed square 2. If using a "bounce drop"--a white surface upstage of a translucent drop or scrim, bounce focus would be lights facing US, even though they're lighting the drop DS of them. Often achieve a more even wash this way.