Be picky about what you pick up. Gloves, jewelry and some one handers are the only inventory slots that are not best served by a legendary. Obviously you pick up all legendaries, but rares will not sell for huge amounts unless they are pretty much trifectas, or absolute BIS items. In my experience, I have made much more money selling trifecta gloves and jewelry than any other item, and I still have a backlog of stuff to put on the AH, mainly due to increased legendary drops and trying to get rid of all the other junk that I have accumulated before I figured this out. After monster power 1, everything can roll insane stats except for armour. I highly recommend picking up only gloves and jewelry, and ID’ing your stash once every few runs. A good analogy is lottery tickets. Would you pick up a thousand lottery tickets with a chance of winning a small amount, or fifty lottery tickets capable of winning huge amounts.
Gear right. Stack all the stats you need (usually crit %) but also don’t go for small upgrades. If you do, you will waste huge amounts of money getting to the same point that someone who rarely upgrades will get to, but you will outspend them by a wide margin. Get that massive ruby in your helm. This is probably the number one slot for an expensive gem, even more so than crit dmg for weapons. I feel an extra few percent XP will get me through paragon levels much faster than a slight increase in damage, which I will honestly get in a couple of paragon levels due to stat increases anyway. Get a hellfire ring. Get a leorics. If you can’t afford a leorics, get a stone of Jordan. They cut through elites like butter, and you will be spending most of your time battling elites anyway, so it makes sense to cut them down quickly.
Ignore chests. And other environment objects. Resplendant chests are a different matter now they effectively act as an elite mob in granting one NV stack and loot. Hitting environment objects for loot is always a bad idea. Hitting them for fury is not that great either. I figure out you gain possibly half a second extra on WoTB for hitting one, so long as you are not already at max fury. If you are inefficient running up to it or away from it in any way whatsoever (slightly wavering line instead of a straight line), all you will do is lose time overall.