The only true foolproof method, though, is to get into the habit of having your own gear stowed away in your carry on by the time the landing gear comes down and always checking the seat area and seat pocket for things you may have stashed there.
This can't be repeated often enough! It pains me to see posting after posting from travelers who have left their laptop/ipad/other valuable item in a seat-back pocket or hotel room.
After having forgotten things myself, I now make it a policy to check every cubbyhole, seatback pocket, overhead bin, and compartment near my seat before I leave the plane, regardless of whether I remember putting something there. It really needs to become a habit that you do 100% of the time, no exceptions. Once in a blue moon, it will be the one time that you are thankful.