Step 1: Be a Lalafell
Step 2: Bite some ankles
Step 3: ???
Step 4: You win the game!

Wait, what was the topic again? Oh, right. IMHO a good player has a fairly good idea how each job works and then plays in a way which benefits the entire group. For example the tank turns Calcabrina to face the groups BLM during the shield phase instead of making the BLM run around. A nice player is, well, not a d!ck.