Know how to deal with Durant and Cresselia. With the metagame now having Cress and Durant unbanned one should be knowledgable in what to do when faced with these pokemon. The biggest mistakes you can make with these guys is A) having an unprepared team and B) letting set up. Without any boost both pokemon are manageable. They become real threats when they acquire some boost. So it is best to also try and stop this and Cary checks.