This achievement will generally come naturally through playing, however, if you want to farm it the easiest way is during the mission Kai gives you when you first meet.
You'll be sent on a mission to retrieve some parts from green spiders, and your objective marker will be a spot with a ton of dig sites. The goal of the mission is to destroy a spider, but what you want to do instead is extract their cores. Dig sites keep "spawning" until you get the quest item, so if you just keep extracting cores you'll eventually get enough to get the following:
This is also an easy spot to farm the following achievements: