I start by running a piece of tape, end to end, just inside the posts of the tuners, set my middle machine where i want it, (I've angled them up or down as well as straight ) and then drill my screw hole. Measure the distance in and draw a line down your tape. Assuming your post holes are in line, equidistant from your headstock edge all you do is turn the remaining tuners until the screw hole has your line in the center. Granted , I've only put the gotohs on 4 guitars so far....they are my tuner of choice now though, I have had no problems.
The " wiggle till they look right" adds that element of risk tho.
