1. Go to Home depot, and buy a chain. I recommend this type, which costs about 60 cents a foot:
Want to do it yourself? No problem. Here are the steps:
Each link is about 8 MM in diameter, which is ideal for good traction in snow and ice, but not very disturbing when walking on an exposed surface.
You will need about 5' of chain for a single adult shoe, and about 4' for a child or small woman.
Don't forget to get good cutter for the chain, and get some small (4") cable ties too.
2. Many shoes have a back loop, like this one. It's very important, as it holds the chain in place on the back of the shoe. I can't imagine being able to secure it without these, so verify in advance:
3. Pass the chain through the back-loop to the middle of the chain. Pull it downwards under the hill and cross it. Then pull it upwards in front of the leg and cross it again. Pull underneath the shoe and cross a 3rd time. Pull back to the top of the shoe, pretty close to the the front. I recommend you do it once before cutting the chain to make sure you don't run too short. Also, most shoes have grooves in the sole, which can help keep the chain in place.
4. Once completed the 4 crossings, tie the end of the chain together using cable ties. Make sure it's tight, but not too tight so that your foot can still fit in there. You can also use some twist wire or a small lock, but small cable ties can also be used to secure the loose ends of the chain so they don't rattle too much.
5. Use one more cable-tie to tighten the front cross to the middle cross, as can be seen in the top image. Again, care not to tighten it too much. Optionally, you can use 2 more ties to tighten the back under-cross too.
6. That's it! God speed - this simple and cheap solution gives a surprising amount of traction. The main disadvantage is finding the right amount of tightness. Too much, and it will hurt your feet or cause damage to the shoe itself. Too little, and it will come apart at the worst possible moment. Also, a word of warning - I recommend against driving with these shoes. The chain might come apart midst-driving and get caught around the peddles. Use at your own risk!