Vanguard. Get the maximum marks every week from strike playlists. Buy the lowest cost (65 mark) armor pieces first. Make sure you're doing at least 1 public event a day to start stocking ascendant shards. Once you level up a bit from blue gear start doing the level 24 and eventually level 28 daily heroic story mission to get more ascendant shards. Shards are not a problem once you start raising, but until then you're going to have to grind to get them.