.......As for your drawing...you have the double-pole switch/breaker drawn correctly.... you are feeding two ungrounded conductors...L1 goes top, L2 to the bottom. Now you show two neutrals... that kind of defeats the purpose of a multiwire branch circuit.
Ball in your court now
So you've never hooked up a 240 air conditioner compressor, or electric water heater?Mr. Deep Cover, the whole point of a multiwire branch circuit is to utilize all phases.