Verticality. I often recall the disappearing pie. My mother had made a pie for me to take to a high school event. I left the house, pie in hand, but my hand lost grip on the front steps and the pie disappeared. It was not on the steps, not in the surrounding garden or walkway. No pie. My parents came out to help hunt. No pie. The next morning, in the light of day, we found the pie standing on edge, vertically, facing the porch wall.
Since then, I have frequently lost something that hid during many searches, only to find said object snuggled up to a vertical partition in handbag, drawer, closet.