How do you guys level scopes?

[Snarf]

I set the rifle in a vice or holder and use a bubble level to get it level. Then I hang a plumb bob in front of my door. Then shine a flashlight from the objective end of the scope to project the reticle onto the door. Focus it by using the reticle focus ring. I put another level on the scope turret just for reference. Then I turn the scope until the vertical line and plumb bob are aligned. Snug down the rings and double check before torquing them down.

That makes sense. That way you don't have to assume the scope turret cap is square to everything else. Just to satisfy my curiosity, do you ever come across a scope where you level against the plumb and get bad results from the level when you do your sanity check?