If I am remembering correctly, the first trick I thought I invented on my own was a Coins Across with a wine glass, only the glass was a sealed mason jar placed on the table, and it would be out of my reach. The method I came up with was clever in theory, but impractical in practice.
I had made these little coin pockets from green felt that aligned like a card index, and placed them in the interior of the lid. Each half-dollar had an invisible thread attached, and the bottom of the jar had a hole drilled through it. (I always assigned my mom the strangest errands while I was at school—like a visit to the glass shop–thanks, Mom.)
The invisible thread was threaded through the hole, and one by one, I would yank each thread as if I were trying to pull a tooth, and a coin would slip out from its pocket and fall into the glass. During most attempts, however, the jar would fall over as well, demanding two hands, which defeated the hands-off premise I was going for.
My 15-year-old self concluded that this method was not going to work, and I began to brainstorm more mechanical ways of achieving my idea. An extensive search for clock mechanisms and Coins to Glass routines eventually exposed me to Robot Coins, which is said to have been originated by Ken Allen in 1959.
More deep searching led me to an image of the Robot Coins gimmick on Tannen’s website. It was a beautiful piece of apparatus embedded in a card box that sits on top of a wine glass. I was saddened yet excited to see a fully functioning piece of equipment that performed the same feat I had set out to invent, and it was developed over 50 years before I was born. I quickly came to the conclusion that anything I created on my own would not compete with the advanced mechanical methods that were already out there.