While leveling, you can have some great advantages when there is Mage. Obviously, many classes have their own merits and demerits, but when it comes to Mage, it proves to be a great to level as he can teleport to cities from one to another continent, make his own food and water, and is able to Blink, which also decreases run-time. However, there are different opinions to address it as the best leveling build. Some would vow with the Frost build since it is more mana efficient. Nevertheless, I would prefer a Fire/Arcane build only because you can bring down the enemies faster and the Arcane tree will benefit you with mana regeneration and more stats.
However, let’s begin with the full Fire talent tree.
Mage Leveling Build: Fire
With a Fire Mage, you have a Fireball or a Pyroblast to kick off the attack, and go on shooting a 2nd Fireball followed by a Fire Blast. Still the target is not dead, so you can proceed with Frost Nova by taking a step back and making another Fireball+Fire Blast combo. You have the Blast Wave and Dragon Breath at a later level to do the finishing touches too.
The reason behind not taking Improved Scorch is you have to wait for the Hot Streak talent and until then you cannot use Scorch. For leveling purposes, Molten Shields, Blazing Speed and Fiery Payback are unnecessary. Many Mages skip choosing Impact, but I used to do it for its pretty leveling. In case you are successful in managing three or four Fire based spells before the mob reaches you, you have the chance of 30-40% of stunning the mob for two seconds before he advances more.
I took a bit of Frost because of the reduced mana cost of both Frost and Fire spells through the talent called Precision. My other favorite option is going for the nice combination of Arcane+Fire.
Mage Leveling Build: Fire/Arcane
This build has a mana preserving advantage because 60% of the regeneration continues while casting. You will also be surprised with the amount of critical hits you will get with this build which will also refund 30% of the spell’s costs. You will also have 10% more Spirit and 15% more Intellect. Arcane Concentration will allow about 10% of your spells to be cast free of costs.
Instead of giving you AoE spells like Blast Wave and Dragon Breath, this build mainly deals with Fireballs, Pyroblasts and Fire Blasts. A good choice for AoE purposes is about boosting a bit of Arcane Explosion. With Arcane Power and presence of Mind, you will have two excessive great abilities, which will be likely to bring out high burst damage as per the needs.
You can opt for going full Frost but specifically in the first 30 levels, and you will be much worse than the builds said earlier. Shatter is the nice option, and further you got Icy Veins, Cold Snap, Water Elemental, etc. However, the damage of the aforementioned things will be higher than that of the output of this build.