There are many ways in which to find a lost item. The earliest recorded method I could find was actually written by William Shakespeare in The Merchant of Venice and was later adapted into a common folklore belief involving marbles. At one point, Bassanio is speaking with Antonio of his youth.

"In my school-days, when I had lost one shaft, I shot his fellow of the self-same flight The self-same way with more advised watch, To find the other forth, and by adventuring both I oft found both."

For those that do not read Shakespearese, the translation to modern day English is this.

"Back when I was in school, I used to do archery, and sometimes I'd lose an arrow. When this happened I would fire another arrow of the exact same type in the same direction and watch really closely as to where it landed. Then when I went after it, I often found the first one."

Since then it has been adapted to all sorts of things... though the only one that comes to mind is marbles. Anyone who has ever played marbles outdoors --or indoors with a lot of furniture around-- has felt the trauma of losing a purrie or a steelie, or even... god forbid, a masher. The way to find it was to find a marble of similar make and material and shoot it the same direction. This actually works even better than the arrow method, because generally spheres will tend to follow contours, and gravity will draw them to about the same area if it is uneven ground. I heavily suggest trying it sometime, as an experiment.

And that, my friends, is how you find a lost object. Thank you, Mr. Shakespeare.