Act like a townie :

-Don't post too much or draw too much attention to yourself
-Don't defend yourself too much, use a logical defense, don't appeal to emotion
-Don't behave too differently from previous games

Other tips:
-Go invisible (I'm keeping it on for good, again )
-Kill your the best 'detectives' first, especially those who will lose interest in the game if they are killed
-Try to figure out who the doctors/detectives are