So I've been surfing the mmowned threads for a while now and I FINALLY found an exploit of my own worthy to post.
When you're doing the Erratic Sentry quests, you have to be grouped up with another person, and if both of you hit your Attuned Crystal Cores at the same time, it will count as two instead of only giving you the one you just killed. I haven't tried this with more then 2 people, but I'm sure it will do the same thing with 2 or more.
Anyways, enjoy the quicker quests