After you get to 70 you should:
Collect everything and salvage them but make sure to quickly hover over the loot before you salvage them! This doesn't take long. Also comparing and changing gear during the run is not advised, especially not in groups. It slows the pace down. Good place to target farm materials is the Battlefields of Eternity on act V, there are also a lot of elites there, and chests. Be sure to clear that area if you want to target farm WHITE ITEMS.
Do not spend too much resources on early item re-rolls and if you happen to get the Ramaladni's gift, save it untill you get 1) GG weapon 2) another gift. This gift gives you essentially a 5th primary stat on weapon, a socket. If the weapon already has a socket, you need to reroll that socket into something else. Here is a tool to calculate maximum damage for a weapon. Also remember than taking gems from armor costs gold, so try to manage gem upgrades in a way that you don't need to take the gems off you armor many times thus minimizing the removal costs.
More content is better than harder content, so speed is the key. Don't force too high difficulty. A small tip for monks: the momentum passive lasts 6 seconds, if you drop this buff often then you are doing too hard difficulty. Also as a Barbarian if you drop rampage passive stacks, again too high difficulty.
Use your bloodshards that are capped at 500 per account to gamble items from Kadala. You get bloodshards from bounties, rifts and greater rifts. Good thing to gamble first is the essential set pieces like SWK set for Monks etc. Weapons cost a lot, but you can get endgame GG weapon from Kadala. Gambled items can be ancient.
Bounties should be done on T2 for extra legendary chance. Playing rifts instead of normal maps is more beneficial since there is increased legendary chance while you are in a rift.
Be sure to check appropriate class-spesific diablo reddit for more info, there are guides and wiki on the right hand panel on each class sub-reddit http://www.reddit.com/r/diablo3monks http://www.reddit.com/r/diablo3barbarians http://www.reddit.com/r/diablo3demonhunters http://www.reddit.com/r/diablo3wizards http://www.reddit.com/r/diablo3witchdoctors http://www.reddit.com/r/diablo3crusaders