Be respectful (duh).
Take the lead from myself or any of the mods when it comes to certain conversational topics, spam, etc. It's generally pretty lax, but listen if someone says to move on.
If you're in my chat, don't queue into me. Whenever I watch another streamer I intentionally avoid them (which isn't hard to do given typical queue times), and I expect the same courtesy from others. I understand accidents can happen, but don't make it a habit or be flippant about it.