For cool weather riding, a little trick I use is to wrap a piece of paper towel over my toes as I am putting my shoes on. That, along with a pair of toe warmers will keep my feet warm to about 0 C. I use Look pedals, so the thick plastic cleat does not act as a heat sink. For winter riding on my mountain bike I have a pair of heavy leather winter cycling shoes. They are a somewhat loose fit so that I can wear thicker socks without cutting off circulation. We regularly ride in temperatures around -10 C in the snow with no difficulties at all