GoPro packaging materials have long been prized for DIY mounting purposes. Competition aside, I was quite impressed with the simplicity of this model. The design uses 3 zip ties (aka cable ties) to form a loop where a backpack’s front strap can be attached. In this case, the pack it looks like some sort of Camelbak-like hydration system. The picture below should explain the concept, but check out the original photo set to see more.
For another use of the GoPro box top, check out this elevated mount using a bike stand and PVC pipe.