Did you know there's not a single shoehorn instructable? I just had to make one. Really, you've got to believe me, the Robot made me do it. This one is made from a spoon and a few hundred hammer strikes. It’s actually more useful than I though it would be.
A shoehorn (sometimes called a shoespooner) is a tool that lets the user put on a shoe more easily. It does so by keeping the shoe open and by providing a smooth surface for the foot and the heel to move, without crushing the shoe's counter (the vertical portion of the shoe that wraps around the back of the foot), in this way acting as a first class lever. - Wikipedia
Update: There actually was a single shoehorn instructable.
Step 1: Flatten the Spoon
Use a hammer to flatten the spoon. I used a nylon hammer to keep from marring up the metal.
Later on I'll use a small ball pen hammer to pound in a curve. I drew lines on the spoon with a marker to show you the hammer pattern I used.
Step 2: Heat and Curve
Mount a large socket into a vice. Heat the spoon with a torch until it’s red hot.
Place the spoon over the socket and hammer the sides down so they conform with the curve of the socket.
Once the spoon is curved, mount a ball peen hammer in the vice and use a smaller ball peen to leave a hammered finish. Make sure to follow the hammer pattern shown in step one.
Step 3: Form the Hook
Heat the handle of the spoon until it’s red hot. With a pair of pliers, wrap the handle around a smaller socket mounted in a vice.
Once you're done, hand bend a curve into the entire shoe horn.
Step 4: Clean It Up
Use a scouring pad to clean up any rough edges. Finish it off with polishing compound on a buffing wheel.