I obsessively look for spent shells when in the field/woods. I'll walk around in a circle over and over until I finally find it. I just don't like to leave them sitting on the ground. Got a box of nothing but hunting trash that I put them in.
A couple years ago I dropped an 8 pointer with a Winchester Silver Tip slug, and recovered the extremely mushroomed jacket from the hide on the opposite side of the deer, the core separated and kept on going I guess. Anyway, that jagged chunk of metal hangs from my neck now whenever I've got a shotgun out with me. I very briefly considered doing something similar after I made my first bow kill, but quickly though better about it.
While cleaning the first deer of the year, we always stick a bunch of fat trimmings on the tree we hang them from as a good luck charm. Everyone has to leave a nice bloody hand print on the tree as well.
---Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.---
---Enlightenment is the ability to take infinite pains---