Being able to do a voice and really embody the character really added to the last session I played (other players, not me). I am hoping to improve my ability to contribute to the table, so I am asking you, my fellow leftist enjoyers of a shared pretend, what you feel is something that has helped "up your game" and contribute to the experience.
Be willing to do something to move the plot along. Take the obvious plot bait. Nothing worse than a group of characters knitting instead of opening the plot box. They can knit forever without taking up any player time. I think it comes from players trying to outwit the GM or something. Very adversarial.
Try to pay attention to the social needs of everyone at the table, including your own. If someone is floundering, see if you can bring them an out.
Learn the rules, especially the ones pertinent to your character. Making lots of attacks? Write down the most common bonuses and penalties somewhere. Stuff like that.