Hi,
I know what you mean,i like to get my unit spot on in the correct place,otherwise it doesnt quite look right.

I actually made a template that was the same size as the one i sent to toplace for my custom units,(i used the plastic moulded piece that used to come attached to the pieces when they were sent out,last few orders i made didnt have this as they were placed in a flat envelope).Anyway i place this template on my head,get the correct position and then mark the front with a eyeline pencil,just with a dot,i use this dot to line up the front of the piece, to get the piece in the right position.You call also measure from your nose with a dressmaker tape,so the measurement would be the same every time,but i haven't tried this.They say the piece should be placed four fingers above the bridge of your nose,but that depends on age etc.

Regards topcat