How do you exactly farm for gold and loot? do you have to be in a higher difficulty?
edited September 2016
Do you mean to get a bunch of loot stashed to put through the cabinet, and prepare for a more challenging playthrough?
For items, it seems pretty rng to me. Just keep playing though until one of the bosses drops a 1000% gold staff, and then you're set. Getting gold just mainly just comes from repeated playthroughs, and having the best gold bonus items you can get. The only place you could conceivably farm loot would be against the higher level unholy type bosses that spawn on the roof before fighting solomon. At higher difficulties I'd imagine you can farm imp waves from these, but I've never bothered.