In reply to Alex1:
Lightweight layers. I get stuff on sale. I have wool under layers, a lightweight puffa jacket ( I have a 200, a 300 and a 400g one depending on conditions, usually I take one, sometimes 2), light ski pants ( similar to Dynafit Mercury ), light rain pants (I have a woman's one because it was light and on sale and fit well enough with full length zips) and I have a few OMM Aeon Jackets as they work so well for me and were on sale. A light buff, a minimal hat, cross country gloves for up, and then proper ski gloves for down if it's cold. That works for me, and has been fine for everything from Northern Norway to traversing 4000m peaks in the Alps. If it's cold I take two puffa jackets and another buff, and some thin wool glove liners. Then I just put on what I need. I almost never wear the rain pants, the weather has to be pretty extreme for that. Most of the gear works for hiking, running and climbing too. I've worn my yellow aeon jacket rock climbing in Greenland, the Pierra Menta skimo race, a mountain marathon, cycling to work and gardening. Yellow duct tape fixes any holes :P.