“What is the best way to thank your GM?”
We’re all here to have fun. A GM is playing the game as much as his or her players. So have fun and show it, let yourself go in role-play. Afterwards tell your GM about your favourite moment. Tell them how it made you feel.
What upsets a GM is bored players, so if you are not having fun feed that back too. But think about what you are feeding back on – it’s about whether or not you were having fun. So don’t criticise their interpretation of a rule just because you know the rules better, or tell them how you would have done something because you are a more experienced GM, rather tell them how whatever the problem was made you feel, and let them work out how to help you enjoy it more the next time.
Be a fan of your fellow players too, enjoy their company and watch them play when you character is out of the spotlight. I don’t mean 100% of the time – RPG sessions are long and everybody needs to switch off for a while, but keep your phone browsing to a minimum.
Above all, have fun.
(Though, if I’m your GM, cash gifts will be accepted)