Respect the weather: if snow is forecast, before you set off, ask yourself if your journey is really necessary. If it is, ensure that you have plenty of fuel, and if you can, put a shovel and some matting in the boot. You may not need them, but together with a vacuum flask and a warm coat, they can make all the difference if you do get stuck.
A mobile phone and membership of a breakdown service are both godsends in bad weather conditions. If your journey has been delayed due to the snow, do not try to make up time by driving faster; find somewhere safe to pull over, ring ahead and then concentrate on driving safely.
Except in extreme cases, motorways are kept free of snow and ice by gritter lorries. They same is not always true of slip roads and hard shoulders, while bridges are particularly susceptible to re-freezing after the initial snow has melted.
Drive on snow as it you are trying to walk on eggs without breaking them. Stay in as high a gear as possible as it will reduce the chances of accelerator movement leading to loss of traction.
Pay close attention to the road surface. If you keep to the left hand lane when snow starts to settle, the weight of traffic will tend to clear the surface. Likewise avoid the right hand lane which will always be the first to become impassable.
When snow or slush accumulates in ridges between lanes, avoid putting your wheels on these unless you absolutely have to.
As a general rule, drop your speed and allow a greater stopping distance when the weather conditions are deteriorating. Aim to use your controls with extra smoothness when the road surface is slippery.