Things to do as a player:
- Be "experienced." If you haven't played before, make sure you've at least read a couple games before jumping into one. Make sure that you understand what's generally going on, theorywise, and that you have at least a decent grasp on logic. Knowing common roles, terms, and situations is pretty much essential. If I went line by line with examples I'd be here a long time, but to respond to Smodge with a recent example, be aware that scum will do literally anything if it is likely to result in them winning, and be aware of the conventions regarding voting, hammering, putting people at -1 to hammer, roleclaiming, etc. More importantly, be aware of the logical game theory underlying these conventions. If you're not sure, ask someone, and be sure to listen to whatever advice and answers you get. Though obviously it's best to ask someone not in your current game, if it's about something neutral like common conventions.
- Be courteous. Mafia is a faction-based social game at its core. There will be lying, backstabbing, treachery, paranoia and mistakes. You'll be scum sometimes, you'll be town sometimes, you'll win some, you'll lose some. At some point in some game you are going to get mislynched for stupid reasons. But it is just a game. Don't take it personally, don't obsess over it, and, most importantly for when you're actually playing, keep your cool when things turn south. Remember that in most cases, you win with your team, even if you're dead. If you're a townie and you throw a fit about being mislynched, not only are you hurting town by distracting them (and making yourself look worse prior to lynch, probably) you're hurting the game for everyone, including yourself.
- Do your best to play to win and help your team. After the game is over, don't take losing seriously, but while you're playing you should not "be okay with a loss" and give up or act randomly or whatever. Play to win.
- Try not to mess up your teammates. This includes a lot of stuff. If you're town, don't lurk or play scummy and thereby invite a mislynch on yourself. Don't make roleclaims that could hurt town without a very good reason. If you're scum, try and be in agreement with each other, and have short and long term plans.