I had been trying to sharpen my plane irons and chisels free hand which wasn't giving me the results I was looking for. So I finally broke down and ordered a honing guide. I ordered a simple one that clamps onto the sides of the plane iron or chisel. I also ordered some 1200 and 2000 grit sand paper. I use spray adhesive to attach the sand paper to a large piece of glass. With the honing guide holding the blade at a constant angle it was fairly easy to get the plane iron very sharp.
Here is the sharpening set up.
I think this is the sharpest I've ever been able to get any blade. The plane worked very nicely with a sharp blade.