"CORRECT" is what you find that suits your personality and style. I never had a chance to learn any procedure in RC flying as I only had 2 "grab the transmitter" lessons back in 1971. Then I was on my own.

I always associate "TRIM" with whatever I need at the moment and holding pressure on the stick to attain that point until I can trim out the pressure. That came from full scale flying.

I hate, despise, abhor, and other not-nice terms digital trim on toy airplane RC Transmitters. If I need a lot of trim I want it NOW. If I need a teeny-tiny amount I want to select that amount, NOW!

For a new airplane, I set up everything as close to straight and level as I can determine on the ground. On that first Take-off, I use rudder to maintain directional control - if the machine wants to roll - until I am a safe distance up, say 8-12 feet. I hold pressure in pitch to maintain a climb angle of from 10-15° nose up (heavier airplanes the lower) until good airspeed is established. Once a turn away from the flight line is made and a downwind line established, I trim for straight and level. As the flight proceeds, then I check things out and go from there.

I don't do any competition aerobatics so all those things that are published I do not do much of. OTOH, when in the USAF and doing a considerable amount of formation flying, I wore out flying glove right-thumb positions every 3-4 flights. Doing formation aerobatics, I kept my airplane trimmed as much as possible, as all those small corrections could be accomplished with the lightest pressure when the machine was in trim. That little trim button on the stick always got a real workout. [sm=tongue_smile.gif]
As an airline pilot I hand flew my machine a good bit of the time at level and also all the time from T.O. to level and all descents.
Did you know that just a flight attendant walking back and forth can cause a real change in trim? It does. [sm=shades_smile.gif]

A well-trimmed machine makes flying much easier. I do trim for my final approach airspeed. Sometimes a tad extra up, because as you break the descent for roundout and the model starts to slow, that requires additional nose-up control pressure. I see many nice approaches resulting in a very bad "landing" because the RC pilot ignores:
1. The use of more up elevator in the round-out will cause lower airspeed which results in loss of wing lift resulting in a nose drop with more up needed.
2. So many RC pilots, especially newer ones, will release any nose-up pressure when making some small aileron correction. OOPS, nose first landing.
3. Pilot has some power on and pulls throttle to final idle, with no increase in up-elevator. Remember that during the landing process, when the final reduction in throttle is made, the loss of that accelerated air-flow, reduces the stabilizer-elevator's lift force downward that holds the wing in its lifting Angle-of-Attack. Airplane drops, usually nose first.

Good Trim and good feel of Control Pressure significantly reduces the number of these bad landings.