Very important you learn knife edge and inverted. You really have to be comfortable with these to get on with 3D. And remember to practise knife edge with the belly towards you.

eg One reason for this is for practising hovering and torque rolling. These are easy to do, but very difficult to do well (ie for more than a couple of seconds). You will "fall out" continually, and the plane will fall out in any direction and atitude. When if falls out coming directly at you inverted, you need to know how to react instinctively.

I learnt to do rolling circles on my flight simulator first, to get in my head the order and orientation of the control inputs. Now practising on my plane. To improve my contol and orientation, I am flying control line circles and figure eights both up right and inverted (rudder primary control, elevator and ailerons to maintain level flight) and knife edge circles and figure eights on both left and right side (elevator primary control, rudder and ailerons to maintain level flight).

At the moment I dont have a plane suitable for 3D, doing the above with my GP Extra 40. Should have my 2 new 3D machines up and running shortly (GP Cap 232, and Capiche 50)