I fly Mode 1, with a tray (Falcon) positioned higher than normal and I fly long sticks with 2 fingers and a thumb wrapped around around the stick. That's what works for me.
The most unusual method I have seen is David Snow who is the current Masters nats champion here in the USA. He uses a tray positioned very low with super long sticks. He puts his thumbs smack dab on top of the stick and his fingers spread out on the side of the tray. You'd have to see it to understand, and if it was flying season I would show a pic of it. Mike