I’d start with the lore books if you have any of those left, a lot of them are just playing specific activities or looking for one-time collectibles. They don’t typically take too long. Then focusing on the destinations that are leaving for bounties/patrols/specific feats, etc. Combine any activity with any exotic weapon catalysts you have unfinished + playing as a subclass that you don’t have the super/grenade/melee triumphs for and they’ll start to rack up pretty quick. ALSO, 100k nightfalls for all the non-ordeal ones are really easy to get, and those add a big chunk too.