One trick I used, which to be fair was on a rigid, I had the curtain buckles marked on the drivers side and wherever they lined up on the road was my markers.
For example:
4th buckle from back lined up with top of kerb would mean the tail lift tip would just be on the kerb.
4th buckle from back lined up with bottom of kerb would mean the tail lift would clear the kerb.
6th buckle from back lined up with ground was my marker for docks.
8th buckle from back lined up with wheels.