Sam- Went back and looked at you earlier post about slow-rolling the Decathlon. I teach acro in a Super D and would agree it is probably the hardest maneuver to learn initially. I have found the best way to get it across is to have the student get comfortable with inverted level flight to see the attitude necessary. Now, look at the upright level attitude, and think about getting from one to the other, then back upright. It is not necessary to raise the nose prior to starting the roll, but the nose does have to be rising throughout the first half, then coming back down through the second half.
Start the roll from level with simultaneous application of back stick and aileron into the roll, also a little dab of rudder into the roll to compensate for the adverse yaw. As the roll progresses, through the first 1/4 the stick will be coming forward to approximatly neutral at the knife-edge, while adding increasing amounts of top rudder to keep the nose rising. As you pass through knife-edge towards inverted, keep the stick coming forward to keep the nose coming up while easing off the top rudder to neutral at the top. As you start the second half back to upright, the stick needs to be coming back throughout, while adding top rudder to a maximum at knife-edge, then easing off as you come back to level. The roll rate should be constant, so keep the aileron deflection constant throughout the roll as the airspeed will be constant also.
The biggest problem I see is not getting the nose high enough through the first half, this leads to "dishing" out of the second half, usually kind of wallowing off in the direction of roll and losing a bunch of altitude. Alternatively, we get to near inverted, realize the nose is too low and then give a mighty heave of forward stick which causes us to get shot out against the belts!!
So, start level, you don't need to pull the nose up before starting the roll, but it should be rising through the first half and falling through the second. Find the spot on the horizon that seems to stay put and try to roll the airplane around it.
Have fun, Tony Johnstone, MCFI-A