I work outside a lot, recently it's been about 0'C.
I wear merino wool socks
Merino wool long johns and long sleeve top as a base layer.
My recent addition is a fantastic Icelandic wool sweater.
Merino wool buff scarf
Wool hat.
I like leather gloves, jacket and jeans with that.
It's important to have nothing baggy, nice overlaps, layers and always plan to be too warm and take things off as you go. Wool stays warm even when wet, temperature regulates too so you rarely are over warm.
I got this coat, the ThruDark Shroud last year and it's preformed great. Tough, entirely waterproof and very warm, huge too: I'm 6'6 and the S/M is almost big for me, see: