In act one pick the quest "Trailing the coven" and up to part 2 or 3.
Go through the quest until you find Leoric's courtyard. Now for the farming.
hit the checkpoint right as you enter the courtyard.
Search the courtyard for any elite packs or rare monsters
leave game
resume game
There is a 100% chance there will always be a elite pack of mobs spawned here or a rare/purple mob. sometimes you can get 2 elite packs or elite pack and purple or rare, or any combination. They are ALWAYS cultist type mobs so they have very low health and die very quickly. A run should take no longer then a minute or 2 and the drops are decent.
Also there are Shrines that can spawn around. Often I have seen them as Fortune shrines. In the pic included:
Red Circles= shrine spawn points
Blue Circles= Mob spawn points
ENJOY!