I have been needing a pair of warm mittens for years and decided to make my own after scouring the internet for a reasonably priced, high quality pair made in the USA.  During my search, I found several websites selling mittens made from wool sweaters, and I said, "Those look easy to make, why don't I make myself a pair?" 
At the local second hand store, I purchased several 100% wool sweaters of various colors.  Before cutting the sweaters, I shrunk them in hot water followed by high heat so the wool fibers would get really tight.
The insides are lined with warm fuzzy fleece.
To date I have made fourteen pairs of mittens to sell at the Wild Ramp and for giving to friends.  
Adding a button to the mitten cuff gives the mittens a finished look and keeps the cuff from folding down.  When I add the button, I sometimes don't stitch down the cuff.
This video provided the best tutorial that I found on the internet.  A printable pattern can be found at: http://romancakedesigns.com/  I found this pattern to be a little small for my hand so I made the pattern a little larger.











