I prefer the wall/ garage door setup as well. I Pull up close too the wall and mark off a + at the center of the beam. pull back 20 feet or so and make the beam hit just under the + and a little to the right on both sides.
This^
A friend of mine has the Hoppy headlight aiming kit that was a required GM tool at every dealership. It includes things to calibrate them to compensate for floors being not level. Once they are calibrated, each one has internal mirrors that reflect the view of the cross-hair on the opposite side headlight it’s a pretty slick setup.
Anyway, in the instructions it states the DOT regulations for whatever year the tool was made that the passages side headlight is suppose to be calibrated with a one foot drop for every 50 feet. The drivers side is the same, except it is also to be aimed to the right 6 inches from straight ahead. I assume that’s so your drivers headlight doesn’t blind oncoming traffic
You can do something similar at home easy enough. Find a smooth flat, level parking lot. Turn on the headlights, pull up as close to a building as possible. Put a tape mark on the wall the center of the light beam. Back up the truck 50 feet, adjust the pass headlight so the beam center is a foot lower than your mark. Do the same on the drivers side, but adjust it towards the pass side 6 inches.