What clothes to pack for a month in Europe in the winter?

I'm going to be on vacation in Europe for a month in late November, early December and I'm wondering what clothes I should bring. I'm only wanting to bring a carry-on bag and so it'll be a limited selection.

I want to look good, but I also don't want to be ironing every day, so there needs to be some strategy to my choices. Are there certain brands of shirts that I can wear without ironing and get away with it? One advantage of the wintertime vacation is that it could well be that I'm wearing a sweater every day, so that could cover up some degree of slobbyness.

One piece of clothing I have that I think i'll could make use of are Icebreaker undershirts. They're warm and they dry very fast, so I can probably easily wash those in a sink and have them dry and ready to wear again in a few hours.

I haven't decided what cities I'll be visiting yet so I don't know if it'll be a mild winter dressing for Italy or heavier apparel for northern european cities.

bring a sweater.

Where in Europe? The tip of Italy is very different than Norway?

A sweater, leather jacket and a scarf should take care of you in any but the coldest climates. Certainly London, Rome, Paris, etc.

if by Northern Europe you mean Scandinavia you're gonna need some serious outerwear. Otherwise a good coat and some quality layering + gloves/scarf should be enough