1. Make your winter boots into minimalist boots! (see previous blog entry). I am actually in the process of doing this, and will report back regularly on their status over the winter months.
2. Keep your shoes off in the house in winter. Walking around barefoot can maintain that muscular strength you've developed over the summer. We podiatrists see a rash of plantar fasciitis in the spring/summer because people take their weak, atrophied feet out of their thick, supportive boots and put them in flip flops with no transition. To prevent this, keep the feet strong.
3. Pick shoes based on my shoe selection rules 1. Zero drop (heel shouldn't be higher than the forefoot), 2. No toe spring (shouldn't be an upward curve at the front of the shoe), and 3. Wide toebox! (again, the hardest qualification to find in most shoes. The ones that do this well are: basic crocs, altras, stems, vivobarefoot, and a handful of other shoe brands). Vivobarefoot makes a good waterproof winter boot, and you can find moccasins and mukluks that fit all specifications, but they aren't waterproof.
5. Functional fitness indoors. Keep hitting the gym with your five fingers or other flat bottomed shoes. Besides being good for the foot alone, they put your entire body in better alignment for lifts, especially if you are doing crossfit (see previous blog post on this). Better yet, if you have your own home gym, exercise barefoot (or see if its acceptable in your public gym--its much more sanitary than bare hands on all the machines!). Laird Hamilton is among many who do this. (Check out his youtube workout session for good functional fitness exercises: http://www.youtube.com/watch?v=s3sMjz6dtX0&feature=related).
6. Keep doing all the "transition to barefoot/minimalist exercises" I've mentioned in previous posts: hip flexor; calf/achilles; bottom and top of foot stretches, and eccentric calf; toe-push; towel pickup; heel walking; and one-legged stand strengthening exercises.
7. Exercise the feet in the boots. If you have to be in big clunky boots outside for work all winter, first make sure you pick boots with enough room in the toebox, and that have zero drop heel:forefoot ratio, and with a thin sole as possible. No matter what, do toe curls, and big toe push exercises in the shoe several times throuought the day--it'll help keep those toes warm too!