Strike playlist. Level 20 and up

Most of mine were from the Crucible. But they were rare and I hit the lvl24 wall. But now I have rank 2 at FWC and I own 2 legendary pieces and my lvl is 25 now. PS - read this like a commercial

The first moon mission when you reach the cutscenes keep killing all the thrall, die after they are dead repeat I got like 20 rare and 5 legendary last night, a missile launcher and HMG

Every time you do a strike on the playlists you should receive a new item, not necessarily better due to the random nature of the drops. Other than that it's just down to slogging away and hoping for a decent drop. There is always your Vanguard if you have enough marks, I bought a piece of chest armour last week that I think will be hard to replace any time soon. Good luck and don't get dismayed, I got stuck at level 21 for 2-3 days until I bought that chest armour and then ended my 4 hour session at level 25. That was Saturday, and I'm still 25 with me playing at least 2 hours every day. First game that's made me go back to regular gaming in a long time.

The strike playlist is how I got most of my pieces.