I've found Muck Boots to be great for keeping warm toes. This year I got a pair of the "Arctic Sport" and they have done me well. Another option for cold toes is to use hand warmers in your boots. Tape can hold it in place, or use two pairs of socks and put the warmer between the layers. (not great for walking as they tend to slide)
Also, a good ski mask helps to keep the neck warm.