a basic farm build has Gold Find & Luck at Cap. you can add Item Drop to Cap for more Loot.
for better farm build performance, getting all 6 Perks can help a lot.
after all that, using the Sets Nadroji (with or without the Nadroji Bonus), Eternalized, Crystalline, or Mythical, in any combination you want, can also improve a Farm Build. many players just use one of these to make a focused farm build for certain items.
there is even a Pet Farm Build…
the first part is before Patch 3.0, and later in the Thread there’s an update for Patch 3.0.