I have been playing with these things since '71, that may make me an old schooler. I have always flown with index finger and thumb. Allows more control and if you get your hands on an airplane that is way out of trim you can set a new "center" on the sticks and save the airplane. Happened many time in the old days when I used to test fly other guys planes.

I recommend this way but you should go with what feels right.

Hank