even the first tier of unrelenting force will stagger most humanoid enemies, and whirlwind sprint is useful for closing gaps. it's more difficult when enemies use frost-enchanted weaponry, but nords and bretons have an easier time dealing with frost-based damage.

Use fire spell or fire enchanted weapons?

With mage types I always try and run them down first before they can do too much damage. If there is a mage type I will sprint in close and hack their head off. So I am not being dealt elemental damage or letting them heal themselves too quickly.

There was this one time, when I was pinned behind a rock near a fort full of necromancers on the way to Winterhold there were two or three of them in various positions so I could not escape and everytime I charged them, they would hit me with their frost spells which slowed me down enough that I couldn't quite reach them with my dual swords. I tried pot shotting them with my bow, but I am just not enough of an archer to take down a mage that keeps healing when his health is low. After getting killed a bunch of times and reloading, I remembered my wolf blood.

Werewolves move fast enough to avoid those ice spikes pretty well and one or two of those spells doesn't seem to slow them down much. One mauling blow sends those frail mage bodies flying like ragdolls and then you can rip them to shreds quite easily. That wolfblood sure saved me that day. Although it is not something I would use all the time, it sure can get you through a tough mage battle in a scraqe.

Now I have a 50% frost resistance necklace and my alchemy skill is high enough to make some good frost resistance potions so the frost spells don't bother me as much as they used to.

You need to close the gap very quickly and kill them very quickly. Pick any of the following, but make sure you have both quick kill and closing the gap.

Slow Time (For quick kill. Your steps are too slow in this mode.)
Unrelenting Force (For closing the gap. Use full power.)
Whirlwind Sprint (For closing the gap.)
Spellbreaker (For closing the gap. If you don't know what this is, it's a spoiler to answer.)
Ward Absorb (For closing the gap)
Truckload of potions (For outlasting.)
Follower tank (For outlasting.)
Conjure Dremora Lord (For outlasting.)
Enchant your sword with Paralysis, and Stamina Absorb. It'll Paralyze the target, and while it's down, you can power attack as much as you need, because you won't run out of Stamina. (For quick kill. Requires Enchanting lvl 100.)

The shout Unrelenting Force is very useful against spell users, that will send them flying and stun them for a while, giving you time to close and kill them with your weapon.
Slow Time is another good shout for this, but harder to come by.

Other than that always watch out for necklaces of frost resistance in merchant inventories. You can have the necklace hot-keyed and put it on when you are facing one of those mages. If you need a boost on top of that keep a couple of resist frost potions in your inventory.