As the frostbite is about body liquids circulation - anything what promotes it is helpful, and what restricts it is dangerous.

E.g. the shoes and clothing should not sit on you too tight. Most cold-inexperienced people overlooks that when using the too well known multilayer principle to quickly improve the clothing insulation. If you add too much thickness under your regular outer shell clothing or manage to fit your leg with 3 socks on into your regular footwear - you might severely restrict the free circulation of blood, thus welcoming a frostbite.

The body extremities are most vulnerable to a frostbite. But in most of the cases, all you need to prevent it is to promote the circulation periodically. Just move your legs and arms wide and fast when possible! It's even worth the effort to take off your shoes and socks (even when it's -20 outside but no wind) and massage them with your bare hands intensively.

However! If you have got an obviously visible frostbite already, don't try any massaging, as you can severely damage tissues further with ice crystals formed in the cells. It's better to "defrost" it first by getting affected foot/hand/nose as undisturbed as possible in contact with cold water, and then warm it up very slowly (add hot water a bit after a bit).