From only a handful of plays I've gathered that a few moves might be to
- If you are on the good team, kick things off with full disclosure such as "I am the seer and I know for a fact you are a villager" to make a play to rightfully gain that person's trust. The immediate downside I see to this could be a claim from a troublemaker that your card was switched, making it just as convincing to that person that you are no longer the safe card you claim to be.
- If you are a werewolf, take a stab at claiming one of the roles and run the risk that someone is that role or knows that role was in the center, and deal with the "my word against his" situation that could ensue.
- Make an non-fully disclosing claim such as "I know you're a good guy" to gain someone's trust but not openly say you are the robber and now have their former card or you are the seer and looked at their card (as a means to protect against the troublemaker claim in point 1). This might be useful if you are the werewolf to lessen the chance you're called out for lying about having a specific card.
Are there other common basic openings? I've only played twice, and only with 3 players so my thoughts on strategies are mostly a thought exercise and not from experience. I did notice some paralysis in anyone making an statement, though.