1. Create a character concept and try to play it without metagaming. No one is expecting Shakespeare here but try to do what you feel your character would and inject fun dialogue in terms of things he would say. If you're playing Jayne be crude. If you're playing Han be a redeemable rogue.

2. Don't argue or fuss. If you don't like a rule or a GM decision complaining once is enough. Don't hunker down and cry about it all night. It just brings everyone down. In the end it's just a game and the majority of the time the GM is going to try to work with you so your character can be a hero.

3. Get to know the rules. Show some initiative. You don't have to memorize the book but at least get to know the mechanics you plan to frequently use.

4. Have fun with your character! Come up with a fun background and look for the hooks where your story advances. The more material you give the GM through backstory and active game roleplay the more he can write for your character.

5. Do not make fun of major villains or plot points. The nemesis you're giving a funny nickname to might have been taken several sessions for the GM to set up. If your character would fear him then he probably wouldn't make a joke out of it.

6. There are always alternatives to fighting. Think. Heroes go outside the box. Be the A-Team. Be MacGyver. GM's love when heroes come up with left field ideas even if it means the plot has to take a side track. I love it when engaged players figure out a way to save the day without a D&D-style slaughter!