With silent casting, I will not draw any attention if using destruction. At early game I will sneak first and if I draw attention for some reason, I will cast destruction until they come up close and I switch to one-handed to finish them off. With frost spell, I can slow them down and they won't have enough time to reach me. Like MrBuio has said, with Conditioning in Heavy Armor, sneaking could work. Only problem, it takes a while to reach 70 skill. Heavy armor is good for additional protection just in case I mess up and they look cooler, too. I want to wear full Daedric armor and it is another reason, also.