What I would like to do instead, is suggest a good habit to get into when you shoot: snapping a frame or two of your model actually holding the signed release.
Now, every photographer will eventually figure out the way they like to work, but I almost always prefer to have my models sign their releases before we begin shooting. I'm easy-going, my sets are generally relaxed and fun, and most importantly, I have a laptop set up at some point to proof images. My point is there is a fairly high level of trust throughout the whole process, and the majority of models agree to sign without actually knowing precisely how they will be photographed.
One day it occurred to me that photographing the model actually holding the signed release would make a nice, convenient insurance policy, if you will. I have no idea of the legality of the photo should the original document become lost, but having the image right in the same folder as the rest of the shoot does a lot to alleviate any confusion or misunderstandings down the road. It also makes a very good reference file to send along to clients or publications that require documented releases of your models.
Model Robert Pate wouldn't dare deny signing his release as long as I have this!
As you can see, it takes very little effort to find a small piece of foamcore or cardboard (heck, even a small reflector) and attach the release. I like to combine it with my Macbeth Color Checker reference grid, and get both of these mundane tasks out of the way as quickly as possible, so I can focus my energy on the actual shoot.
On the rare occasion there is some hesitation from a model to sign off ahead of time, I simply do all of this at the end of the shoot.
So that's it. Sure, another step to remember to add to a seemingly endless list of steps, but a habit that, once you get into it, will help you be more organized and appear more professional in the long run.
All photos ©Steven Paul Hlavac.