No special tricks. Just run. Keep moving. Eat some big pasta the night before. And breathe.
Take in the view at the top
Tread wisely on the ice
Follow strong and disciplined examples
Dont be afraid to get a lot dirty
Keep those who support you whole-heartedly close
And enjoy it!
That may have been my last long distance race (though I don't make any promises) yet somehow the same "how to" seems to apply generally.