This isn't rocket science.

On a buddy box all that it took me is watching the plane make a full pattern twice while watching the instructor on his transmitter - I knew what the plane was doing because I knew it was making a smooth 90degree turn and just watched the transmitter. For emphasis he did a loop and I saw that even that could be done without full stick deflection even on my trainer.

Nothing beats stick time - after a while you either get it or you don't get it. The plane only does what you tell it to do with the sticks. Move the stick X amount and the planes moves X amount. After a while it becomes second nature (should be only a few flights) to get the correlation.