I got tired of losing the little metal spikes that came with the inflatable holiday stuff and eventually mowing it over. I used Fusion 360 to design a stake that I could easily find if the wind blew too hard or my son messed with the blow ups. I added a small flat surface to allow the user to either step on the spike or hammer it in somehow. I know it's sharp and will probably break, but it will still server it's purpose better than the metal spikes they come with. I suggest an obnoxious color to make them easier to find in the yard (yellow, red etc).