Go through the maps from the white level to the red level as quickly as possible.
SMOOTH early mapping and atlas trees in PoE – Tips & Trick
As soon as you've finished the game's main campaign, the next activity you'll obviously want to do is mapping.
However, since the massive redesign of Atlas was introduced, there have been lots of changes to how mapping works. Specifically, you will now need to allocate passives to your Atlas tree as well.
If you do that, you'll get a bunch of effects and bonuses every time you enter a map, regardless of its level.
