Nigel,
Thanks for that. Heliflight, whose helicopters I hire, do a once yearly mountain flying weekend in Snowdonia. I went last year, and I'll definitely go again this year. As you say, it's knowing about the wind that's one of the most difficult things; I found in the US that I was getting better at it with practice, but slowly. But being at high altitudes, especially trying to land, makes a difference too - not that I really need to know about that if I'll be flying in the UK!