Make sure you have the following in your vehicle: Food, Hot Drink in a Flask, a Fully Charged Mobile Phone, a shovel, old carpet to put under tyres if stuck in the snow, an ice scraper, warm clothes, boots and a blanket.
Make sure you have enough petrol in your tank, and the correct pressure in your tyres.
Keep your screenwash topped up with a good concentrated additive.
Always completely clear snow and ice from your windows before starting on your Journey.