Watch the votes
Who votes first, who follows, and who changes their vote at the last moment. Wolves rarely vote for each other.
Listen to the claims
A player who says they are the Seer is either the Seer, a Fool, or a wolf. When two players claim the same role, at least one is lying.
Use the deaths
Every death tells you a role, unless the group hides them. A Seer who dies on the first night was probably found out.
Learn the roles
The more roles you know, the better you spot a lie. Start with the roles page.