It seems to be different for everybody. Maybe its just a matter of luck of reward. Its not like Bungie would tell you what it is you need to do to get good drops. I'm Level 27 with plenty of Legendary and Exotic. All from just playing the game, doing my bounties and the daily, weekly usual. I've earned my level doing what I do best. Dieing the least possible and always getting the most kills in all my missions 95% of the time. Some people earn it by farming, you can do as you please in this game to get what you need. One thing that for sure isn't something you can farm your way through is Upgrading your armors. You must do the missions that give you the Ascendant Materials. Still enjoy the game. Can't wait until the next Event tomorrow. Lets GO!