If you have a camera with a lens cap, then you know well the lengths you have to go through in order to make sure that you don’t lose the cap. My solution is usually to put it in my back pocket, but I’m always afraid I’m going to break the cap that way. I’d rather not have to replace a lens cap that costs anywhere from $20 on up to $40. Instead you can make one of these Lens Cap Keepers for no cost.
The steps are pretty simple, you use plastic from a shampoo bottle or something along those lines. Then you print out the template and tape it to your flattened plastic piece. The rest is pretty basic and thankfully none of the tools you’ll need are out of the ordinary. The only one that might give people problems is a hole puncher, but you can substitute that with a drill. There’s a full tutorial as well as printable templates that you can check out.
Source: GadgetLab