One of the key components to efficient survival is being able to get multiple uses out of a single survival tool.
While this idea is extremely beneficial to packing a bug out bag (the less crap you pack, the less you have to carry), it is also a useful mindset when it comes to crafting your own survival tools out in the wilderness.
The main reason for this is that you won't have to craft multiple tools, which will take far more time and energy; two resources you may not have in ample supply.
So what do we mean when we say more than one purpose? Well, it could be as simple as using a rock for pounding in stakes or for driving a splitting wedge through a cord of wood.
Or it could be as well thought-out as the multifunctional spindle on the following page.