You can make a great strop cheaply. Or you can do the mousepad and sandpaper trick. Or you can do as HD does, I think his system is awesome!
For a cheap strop (or you can do a mousepad on a handle this way):
-Next time you're at Home depot get a couple of paint stirrers.
-Glue them together using carpenters glue.
-Cut a couple of pieces of leather to fit the width of the stirrers. An old leather belt works great for this (see Goodwill).
-Contact cement the leather strips to each side of the stirrer glueup.
-Load one side with emery compound. (fast cutter)
-Load the other with a polishing compound.
Man, you just saved a buncha dough and got one every bit as good as a Lee Valley.
-To use a mousepad, just cut it and contact cement it to the stirrer.
-Get some 3M spray adhesive from Home depot.
-Spray the mousepad, and the back of the sandpaper
-Wait 3 minutes
-Stick them together.
-3M spray adhesive makes a temporary bond so when you wear out the sandpaper, peel it off and do another round of spraying.
TIP --- When learning to sharpen a convex edge use a permanent marker to color the edge. ****Use light pressure and check the edge every few strokes.*** If you're not getting all the way to the edge, change the angle, not the pressure!!!!
Edit: Oh yea. Use 220 grit paper for bad edges, and 400 for fine ajustments.