Here is a great post from
Foot Guru John Vonhof on
preparing your feet for endurance events.
None of it is rocket science, but it's a concise summary of measures to
take before the race, on the morning of the race, during the race, and
after the race. While targeted towards marathoners, the tips are
just as relevant for adventure racers.
Personally, I'm a big believer in baby powder for my feet.