Walking in powder snow is fun.  However, to keep it that way you need to make sure the wet does not get into your hiking boots.  Easier said than done, powder snow has that ability to find its way in regardless how tranquil the weather conditions are.  The only solution I have found to work is to wear a pair of snow gaiters.  The tip on buying gaiters is to select a good fit and make sure they have strap under your hiking boot.  In deep snow it is just so easy for the gaiter to ride up your leg.  The team at the Hilltrek store will be happy to share their advice with you.