Read the room
Most of the time, if someone calls a vote and blames an individual, they are an imposter. But, on those occasions where they aren't, remember who made the accusation. Bad people like to discover their own crimes so they can blame someone else.
You don't have to vote
Skipping a vote is not a bad idea. It is way better that nobody is ejected, rather than an innocent player. Remember, the imposter wants to kill everyone – your bad vote helps them achieve that.