I've followed Jerry Hossom's advice on sharpening via belt sander and have gotten excellent results in a short time.. and I'm getting better with more practice. For anything except the leather I use the slack part of the belt. Don't forget to cool the blade by immersing in water between each stroke. As you get better you may not need to cool it after each pass on the belt but it's good practice anyway. Here's the link to Jerry's tutorial: http://tinyurl.com/293nmo or
http://www.knifeforums.com/forums/showtopic.php?tid/776367/tp/1/