I keep it on FFA while running by myself, then Group with others. I just loot everything on my main, aside from quest items, and when my main's bags get too full, I just stop and trade grays to slaves and greens/blues to enchanter to DE. I've got 4x20 slot bags on my whole team, so unless I go long periods of time without hitting up the vendors, I hardly run out of bag space. But even when looting trash mobs, I found it faster for me to do it this way than try to get slaves to loot with me, even when grinding SM and other old world instances.