Always vote. Do not rely on others to vote guilty or innocent. One vote could be the difference between saving an ally or letting an evil-doer go free.
If someone is almost certainly a Town role that will be killed the night after revealing, do not lynch them because they are "already dead". They can at least take up the Mafia or Neutral killer's night attack, or even both.
If there is a Jailor in game, it can be a good idea to not lynch anyone if there's no clues. If some people are still voting but not talking about anything useful, use the -skip command to voice your complaint.
Vigilantes - Don't shoot people at random, the chance of killing a Town member is high early on. It's mostly best to save your shots till late game, that way your shots have more meaning have a higher chance of killing a evil-doer.
Jailors - Don't be to hasty to execute people, write down the information and roles they give you and add it to your Last Will.
Detectives - Double check your targets, people can happen to visit someone that die, but not two nights in a row.