This build centers around long engagements and sustained lane presence. We're going to be making the most of our Frostbite trait and the chill effect it applies.

TALENTS:

Lingering Chill is going to increase the duration of the chill by 50%, up to 6 seconds. This combos nicely with Arcane Intellect by keeping opponents in-range longer and letting you regen mana off of enemies even more.

Frostbitten is obvious here; free damage boost for every chained ability (and Lingering Chill makes it easier to chain those abilities, keeping frostbitten going.)

Ring of Frost is difficult to land, but will pay off in spades. You need to trap people within the outer ring; NOT the center. This will trap people in-place for you and your team to spam abilities (or wombo if you have the comp for it.)

Icy Veins and Arcane Power are both going to take some practice to time right, but they can ramp up your damage and cooldown your abilities very fast engaging (or finishing) a teamfight. If you're having trouble with these actives, you can go with Storm Front (a good poking/early engage/zoning tool) and Bolt of the Storm (simply because Cold Snap shouldn't be paying off if you're landing your ring of frost well, and the damage it deals isn't spectacular. The teleport will help you disengage or secure kills that run away.)

Northern Exposure is going to mean you'll want to start opening with Cone of Cold so you can empower your other abilities and stack with Frostbite (and Arcane Power at level 20.) Keep in mind, the vulnerable status WILL effect your team's attacks on that target as well. Team focus is important for this to pay off.

ABILITIES:

You're primarily going to be saving your abilities to chain together (for all the bonuses of Frostbitten.) You can use Cone of Cold with Blizzard as an excellent wave-clear, and save Frostbolt until you have clear LOS to an enemy hero.

Ring of Frost is going to be a valuable play-maker, so place it smartly (when your team has ambushed the enemies, when the enemies dive under your towers, etc.) You want to try to capture more than one person in the ring, and somewhere where they'll be soaking a lot of damage for those 3 seconds of root effect.