When all spokes are mounted and nut fully tightened. Put the wheel axle in and place it on 2 jack stands and you can rotate wheel. I used a marker pen first times. Rotate wheel and let it spin, come When all spokes are mounted and nut fully tightenedoser with the marker pin until it nudge the rim. Sideways as well ass upwards. Upwards use the edge where the tire will rest.
Where the marker pen has marked, this is the stickout, Lighten tighten the spokes that will move rim to other side.You'll see that the marker hits the half of the rim.
When this is done and worst wobble is fixed continue with a dial indicator. The wobble mow might be within 2mm, continue until you see the needle moves within the 0.5 mm area. i cheated last weekend, accepted 0.6mm. The part where rim is welded will be visible when measure. Nothing to correct, the rim is not perfect. My rims have had a bump/dimple 100 mm on each side of the welded area. 100 mm on each side will get same value on the dial indicator.
This is with new rim.
Note! A new rim has horrible deburring where welded and very sharp edges on the inside against inner tube. I sanded with 240 grit paper and painted with silvergray rattle can paint (engine paint)
When wheel is trued, tighten all spokes step by step all around until they sit tight. I did the final tightening 3 turns around.
Tools:
Screwdriver to initial tigtening of nipples
6mm block wrench tighten the nipples
Marker pen
Acetone to remove previous marker pen lines. (They will change after adjustments)
Dial indicator. (I did not use this back in the 80's, pen only until the marker line went all around the rim. Visible how it wobbles too)