I tilt the pickup and listen to the fullness of the output as the strings are plucked. I don’t use a pick, so I lower the bass side of the pickup so it’s not too fat sounding. When I play a chord, I can hit several strings simultaneously and listen closely to the overall balance of each string. If the bottom is too thick, I lower the bass side of the pickup. If it’s not full enough, I raise it. Normally I adjust pedal and lap steel pickups approx. 1/16″-1/8″ on the treble side and 1/8″-3/16″ on the bass side on the pickup nearest the bridge.