In reply to Cragbopper:
Is not just the skills in using sharp point things that's worth getting some accurate and up to date training in, the conditions under which you'll be using then can get complex.
How good is your navigating, white outs are disorientating and scary, pacing is way different through soft snow and/or hard ice, you're going to have Avalanche forecasts as well as weather forecasts to interpret.
It's a bit like driving, getting a pal to teach you can be fine. But, are they going to pass on bad habits that they've just got away with so far, are they going to recognise new ones that your developing? Are they going to be applying the most current techniques and learning?
At a few hundred pounds winter skills courses can seem expensive, the person delivering them has probably spent thousands accessing those skills and knowledge, and the skills to pass them on effectively.