I'd been putting buying off an Edge Slicker for a while. I'm not really sure why, but for some reason whenever I was making an order from Tandy Leather I always considered it but never actually went ahead and bought it. Now I see the error of my ways!
I finally purchased one of these white plastic wheels and it is probably the best $3.00 I've ever spent for my crafty endeavors. It's a basic, little tool but it makes such a difference in giving a much more refined, professional look to my leather creations. It's extremely simple to use: slightly wet the edge of the leather, place it in the groove which runs around the whole of the wheel, and then rapidly move the wheel (or the leather) back and forth to burnish the edge of the leather to smooth, rounded finish. Apparently you can also hook one of these wheels up to a power drill to make this process go even faster, but for the size of my projects that really isn't necessary.
If you happen to work with vegetable-tanned leather (I don't have much experience using it with other types of leather) and don't own this or a similar tool, do yourself a favor and get one!