To farm loot and quickly collect Legendary engrams, head to the Rocketyard area of Old Russia. Find a cave enemies emerge from and position yourself far enough from it so that they will respawn in unending waves when you defeat them. Fight them until they have dropped a reasonable amount of loot, and then grab it all.
First buy the Dark Below, and then go to the post master and collect your gear and sparrow.
Then go to the specials master and there are unlimited sparrows for you and your characters.