I took an existing pattern for this, extended the wrist section and added cables up the wrist and over the mitten flap. The cables add shaping and make the wrist a snugger fit.
For Those Holey Toe-Socks You Just Can't Bare To Throw Away
double the glove
Easy Fingerless Gloves, courtesy of Knitty.com!
mittens
Turn a pair of socks in to gloves.
fooooorever looooovee!!!!!!!! XO