Here's how to make some emergency crampons for walking on snow and ice. They are made out of easy to find chain and paracord and can be kept in a plastic sandwich bag. You can keep them at home, but a better place is probably in your car. The paracord uses an adjustable knot to fit over whatever pair of shoes you are wearing and won't cut into them like an all-chain crampon might. These things give you amazing traction even walking on ice. They could easily save you from a nasty fall.
The two essential supplies would be chain and paracord. These can be found at home improvement stores or discount stores. I used #3 chain which worked well. The size of the chain isn't the most important thing, just make sure you don't get so big of a chain that you can't cut through them with wire cutters. I used a lighter to melt the ends of the paracord so it didn't fray. The spit rings and carabiners aren't absolutely essential, but are nice to have. You can get split rings at craft stores. Consider getting a pair of split ring pliers to hold the rings open when you are working with them (that's the tool in the upper right hand corner next to the rings).