New Game!?

I made a new game at the park today, I call it treasure hunting. In which everybody buries some type of object that stands out in the sand. The goal of the game is to hold all the objects in your hand to win. Bottle caps work best, for their unique size, and color in relation to the sand. For this game, every player needs a unique bottle cap, to prevent confusion, it is recommended to use sharpie to mark the bottle cap. Once the bottle caps are prepared, the players need to find an area of sand, that is reasonably large, and mark the boundaries.

Everybody takes turn burying their object, without the other players looking, once everybody has buried their object, they should all try to look around for bottle caps. The one who can gather all of them, and prove that they have gathered them wins. Players are allowed to try and take caps from other players, so if your bottle caps are not buried, hold on to them tight. You are allowed to rebury caps after they are taken out. Trades and tricks are allowed, but fakes are not.

Strategy:
One key point in the game, is to go for your own cap last, doing so will reveal the location of your cap.
A strategy I like is to pretend to not be able to find my cap, then when the other players come, I "secretly" go to another fake location, then when they notice, I go looking for their caps.
With trades, the idea is that you give someone something, at the same time they give you something. Once, when I had my sisters cap, and she had mine, I secretly buried hers, and took out a random pile of sand, and we did the trade, soon after I got out mine and won the game.