Bob, you are exactly right that 0-0-0 is not what you want although up until recently it was pretty much the standard. I think at some point guys started to figure out that it is much easier to fly precision aerobatics if the airplane were set up to fly more true. I think we have all read/heard guys state that certain aerobatic airplanes are less stable, snap happy, a handful etc. Over the past 20 years I have learned that those comments simply come from the old school that didn't really take the time to learn why their airplanes behaved the way they did.

Lets start with the wing. A symmetrical airfoil needs positive angle of attack to generate lift. If the wing incidence is set to zero then the entire airplane needs to be flown at a positive angle or as we would visualize, tail low. To achieve this positive attitude the airplane would require up trim. Other then not looking right the consequence of this up trim would be pulling to the canopy on an up line, down line and during Knife edge. So with all that said we want to put in some positive wing incidence. Usually 3/4 to 1 degree works for starters.

Engine thrust. Because we put in some positive wing incidence, the airplane will pitch trim well at half throttle but will want to slightly climb at full power ( CG plays a part in this as well. ) To help eliminate this we will want to throw in about 1/2 degree of down thrust. All reciprocating engines produce torque. When it comes to airplanes, the larger your propeller is the more the effect of the engine torque, P factor or spiral slip stream ( Whichever guys want to call the phenomenon) will want to make the airplane yaw to the left. The fix is a few degrees of right thrust.

Stab, I tend to use the stab as a reference because it really is the only thing that should always remain at zero. You never want to carry any elevator trim. This comes from the combination of wing incidence, down thrust and CG. Any elevator trim that you may have when flying upright and horizontal will be highlighted when flying vertical or knife edge when the wing is not under load.

Maiden flight. With the settings described above and your CG set at 30% MAC, take note if you need to add any elevator trim. You will need to determine if it is actually trim or that the elevator was not perfectly level to begin with. Let's say that it is indeed required up trim. Two causes can be possible, one being that additional positive incidence is required or that the airplane is nose heavy. To check for CG, put the airplane into an inverted 45degree up line. Nose heave will have the airplane pulling to level quickly. What I set mine to is a slight pull to the canopy in that attitude. Get the CG locked down as step 1 as it influences everything else. If you are happy with the CG, the stab is set to zero and it still requires some up trim then more positive incidence is needed. Once you get rid of the elevator trim you can see what happens on up lines. Pull to the vertical and go hands off. If the incidence is now correct and you have no elevator trim, it should go straight up without pulling or tucking. Pulling to the canopy means more positive incidence, tucking means less. Next upline should be done looking at the top of the airplane. If it pulls left, it needs more right thrust. It should be able to go vertical about 200' and then slowly start drifting left. Once the airplane will not change pitch trim from 1/2 power to full power and will do straight up lines, it should do a very nice knife edge. If anything it will have a very slight tuck. Most times you can use a rudder to up elevator mix. It usually only takes a little bit. Down lines will want to pull slightly as well. That gets corrected with a throttle to elevator mix. A touch of down elevator at idle.

Sorry for the very lengthy response but aerobatic trimming is fairly complex. It usually takes me around 50 flights before an airplane is really dialed in.