Give a group a name — "Austin", "Kitchen renovation", "Restaurants" — and add items to it whenever you like, then filter the shelf to just that group and search inside it.
Two rules make it work: you only ever add something to a collection after saving it, so there's still nothing to decide at capture time; and items never move — a reel in "Switzerland" stays exactly where it was on the timeline. A collection is a lens over your shelf, not a place things go.