My current wizard specializes in Conjuring... he tends to use spirits like Spell Matricies. "Summon a force 5 spirit. Give it the Specific Spell power. Have it cast that spell on demand. Let it eat the drain."

Sure, you have to eat the drain for the summoning, but if you get 2 services on a Force 5 Heal spirit, you're up 1 set of drain... and a spirit focus helps you resist that drain, no matter what spell you give it.