Autoleveling idea is really simple: you reach the next level
"automatically" and then, you can do this again and again and again till
you feel tired! You must have a look to the wikia.
Quick remind:
1° equip your gear+legion that increase the most of your bars before to leveling
2° level up and use your extra bars
3° switch to your normal gear+legion
4° repeat from 1° when you're close to leveling
Close to next level (few xp left), use a x20 hit on a raid or your quest
that give the highest xp return. The extra xp you get will be added to
the next level.
To help you during the autoing process, the game offer 2 possible gear sets:
Titaran Piper Set
is one of the best leveling set released, purchasable in the Bazaar.
Using the free planet coin (pc) you get every 5 levels, it's actually
possible to purchase the whole set "for free". One piece at time, you'll
autoing smoothly till level 900+ (Legion/General/Troops are not
necessary).
Wild Warden Set
is one of the best free leveling set. You can craft it using your Daily
Assignment Tokens, starting from level 300. Since you need to wait 300
levels, all the process require a bit of dedication. Once you get all
the set, you can upgrade it in the Wooded Warden Set (stam build) and further in the Worthy Warden Set
(ene build). This set should allow you to autoing till level 850+
without spending a single pc, being also one of the best free damage
set!
Last but not least are the troops: with the Tokens from your Daily Assignments you can craft the Bound Spirit Beast (and the upgrade!). Equip your leveling Legion with those troops to increase your bars even more!
The gates of autoing are open: none can stop you!