For Steep turns, use the bug splatters on the windscreen to your advantage. Pick one closest to your line of sight (one straight ahead and at your eye level). Note its location relative to the horizon before beginning, and keep it there for the duration of the maneuver. Works great for rolling into the opposite turn, as it will be in the same location relative to the horizon. This works across a wide range of airplanes, so no need to memorize locations on an engine cowl for each aircraft.
The first part of this video shows what I mean:
Bug splatters are great for off field emergency landing practice as well. Once established at best glide speed, if the landing site seems to rise in relation to the bug smear, you will not make it. If the field remains stationary or descends relative to the bug smear, you have the distance to make it.
[Edited 2012-05-21 22:25:25]