0.4 Poisonburst Pathfinder Leveling Guide

Early boss kill order for a smooth experience:
Devourer > cold witch > hut witch > rust king
Grab Concentrated Area after killing devourer and Escalating Poison as your 2nd support.

In act 1 it's very important to have gear with flat physical damage to attacks. At lvl 11 you want to get a Warden Bow, with %phys or flat phys. Any flat ele rune is okay, wont increase your poison dmg but it can add a little bit of boss dmg as you spam Poisonburst Arrow

Also look at the vendor in town every 1-2 lvls for flat damage gloves, every flat for the build is massive in act 1

Movement speed on boots is also extremely good if you can find them, try to search the vendor every 1-2 lvls. I would never swap out movement speed boots, only replace them with other boots that have movement speed.

Besides that you're just looking for life/resist on gear, but flat damage is the most important on gloves/rings.

!!!!Important!!!!!
Always salvage weapons with quality for whetstones and always salvage items with sockets for artificers orb, this is extremely important for gear upgrades throughout the campaign.

I also personally prefer to vendor all rares for gold to gamble in act 2 and act 3 for better gear.