Good Advice for Good and Not-So-Good People

Cop - Investigate people who talk a lot.  People who talk a lot or people who the mob listen to need to be investigated first.  The reason is simple--you don't want someone who's mafia directing the daily lynching for obvious reasons.  If you find that they're mafia, we can lynch them.  If you find that they're innocent then you know we can listen to their opinions without worrying about a second agenda.

Mafia - Kill lurkers.  Unless you know someone is the doctor or cop, just kill a lurker.  If you kill people who don't post often then you're helping everyone in two ways.  One, you're making the day go by faster.  People who take a long time to post or vote get the boot letting the town reach a majority faster.  Two, you're making the night go by faster.  If someone takes forever to post I guarantee that their night vote will take just as long.  It helps everyone out when you shoot lurkers.

Doctor - Your goal is to keep the people who can win the game for the town alive.  If a cop has not roleclaimed then protect me.  Even if a cop roleclaims, still protect me half the time to keep the mafia guessing as to who they should target.