100% Alpaca boot/shoe liners.  Best thing since sliced bread.  Want warm and dry feet - put these in your shoes or boots.  Wicks moisture amazingly, which also reduces foot odor.   They can be trimmed to exact size with sizzors. 
 
Available in Medium (size 7-10) ($15), Large (size 10-13) ($18) and Xtra Large (size 13-15) ($20).  
 
These are the first thing that have kept my previous frost bitten toes warm.  they can be trimmed for a perfect fit with scissors.