When it comes to walking on ice, you'll want to stick to the purpose-made ones - snow boots or hiking boots with large treads. Also, make sure the soles have deep lugs and patterns that offer additional grip on slippery surfaces like ice. Non-slip rubber soles are considered the safest option. Avoid shoes with flat soles or heels like the plague. The way they're designed, they don't have any grip on the surface making it inevitable for you to slip on ice. Plastic and leather soled shoes are especially notorious for the same reasons.