GMs definitely need to enforce strict "in character" play, eliminate "across the table" chatter, and by doing so - set the scene for an awesome role-play experience!
Magic is like alcohol, the more that is used, the more it causes a hangover later on and the less judgement one has when using it. If one waits a while after casting a spell, things "detoxify." A cantrip or two is like a sip of weak beer, whilst a large creation spell is like a bottle of vodka. Cast something too big and you can die from magic intoxication.