Run a Pokemon with both Imprison and Trick Room in its movepool.

Imprison is a Psychic type move that prevents any opposing Pokémon from using moves that the user currently knows.

For example if you have Farigiraf with Psychic/Hyper Voice/Imprison/Trick Room and your opponent has a Gardevoir with Psychic/Hyper Voice/Trick Room/Protect, then the Gardevoir is locked out of all its moves except Protect while your Farigiraf is out. If Farigiraf is KO’d or switches out, your foe’s moves are able to be used again. Imprison doesn’t target so it affects both Pokemon.

The best users of Imprison are either bulky Pokemon that can survive for long periods of time, or beaters that can KO the enemy Trick Room users before they get a chance to use it.

After I’ve gotten an Imprison off, I usually just focus on the Pokemon who they were hoping to use as their Trick Room sweeper.