Are you trying to mount your iPhone to a tripod such as a gorillapod?
Well, there’s a great detailed DIY guide on how to make an iPhone tripod mount here.
I first started out with plastic from iphone box. I trimmed excess from edge to make it look more attractive doesn’t have to be done. Next , I lined up the Rubber case to find where I would need to place holes for the camera and the screws. I found that the case doesn’t find in straight in needs little bit of an angle to work, it depends on type of rubber case. The best rubber cases I found to work with this is the one’s that have a rubber cover for the home button it keeps the phone in better. After line up where you want to put the holes, you can drill it or just use a knife to make the holes.