First off, I really like Destiny so far, great gameplay, really cool environments and all of that jazz. My one big issue with the game is that it is pretty difficult to group up with random guardians in the world or in the Tower, based on what missions you are trying to accomplish. Here are some of my ideas.
-Create some sort of quick chat ability (similar to Dark Souls) to let other players know you are looking for fireteam members for a specific event, to do bounties, or explore the world.
-A close-proximity based voip would be incredible!
-Create some sort of check-in board at the Tower, where people can put in a temporary request to be invited for certain events or find other people to invite to their fireteams, based on what specific mission they are trying to do, like the heroic weekly strike, nightfall strike, raid, etc. I played World of Warcraft back in the day, when the dungeon finder just put you in with a list of players also looking for a group. Your group leader could then invite someone from that list of players. That sort of thing.
-Crucify me for saying this, but possibly a text-based chat system in the Tower or even else where. Proximity based is fine.
Coming from a veteran WoW player, I think the game could really benefit from a more streamlined appproach to finding other players to group with. Usually trying to randomly invite people at the Tower for something you need to do doesn't work. I understand there is the clan system in place, but more in-game methods for finding players on the go would be a welcome addition.