Need good way to grind emeralds

I need a good way to grind for emerald in the quickest possible way. It dosent have to be insane fast, just sorta fast. I would rather something that dosent need an expensive build because thats what im saving up for, and i am late game and have completed all the quests in the game. just need some ideas

 

If you want something that doesn't need a build, Outer Void

 

erm ACKSHUALLY
-the outer void requires a build b/c if there WASNT A BUILD
built by
the most dead
icated bui ld teem evr mde
u wld jst
bottom text
just FALL IN T VD
BC NO BUILD IS NO BLX
stpd dspg