Create a mechanic in scenes for branching opportunities, where once a single obstacle or character is overcome, new paths are revealed and others lost.

Ex.
I'm running a Mysterious Island, and have the players beginning at the plane crash, but do they search the plane? Make their way down the cliff? Enter the jungle?

If they search the plane, they might discover an object of portent and some other mundane items which I wouldn't want sitting out as Asset cards at the outset of the scene.
If they journey down the cliff or enter the jungle, they shouldn't still be able to search the plane or take the other exit path.