I also have skinny calves and wanted to try to make them look better by increasing muscle. Two things I have done that have worked very well are:
1) As the other comment says, do calf-raises but lift your toes rather than heels. The develops the muscle at the front of the calf.
2) Aunning. I started jogging/running and that alone has taken care of the back of my calves. I also enjoy running now and it is a great overall workout for legs and cardio.
I get comments all the time now about my nice legs!! Good luck!
