When building wheels with very light gauge spokes like DT Revolutions, spoke windup can be a real pain. There are tools to hold the spoke from rotating, but usually good technique (overturning the nipple then backing off) will avoid the windup. The trick is to see the twist. I use "flags" made out of short strips of masking tape stuck to each spoke about in the middle of the length. If you line these up on every spoke all facing in the direction of the rotation of the wheel or all across the rotation direction, it is easy to see when a spoke is turning and correct the twist. I got the idea from building a wheel with aero spokes which act as their own indicators of twist. You can easily see when the flat of the aero spoke is not facing forward. So I figured I could make a simialr indicator for round spokes out of the masking tape. Hope this helps.