I'm a leader on two teams and my treasury making time is usually spent doing treasuries with items posted in specific threads, so that really speeds up doing treasuries. And yes, I use the "Add item to treasury" link which is at the bottom of the listing.
When I have time to do my own non-team related treasuries I just do a search for what I want to do (for ex, items related to Lou Reed) and look at each item that appeals... It really doesn't take a lot of time if you know what you are looking for