First thing to do is make yourself a jig so you can adjust for sharpening every tool you use. The angle is most important, pay close attention to the previous angle and follow that as a general guide. DO NOT get your tool overheated during the grinding process. If it starts to turn dark from the heat, STOP, you'll take the temper out. Take it slow and easy. The ones I have had to sharpen took very very little to put an edge back on.
"Jig" I used a piece of 4x4. Cut the top at I think was 45 degree angle, (looks like a podium people speak/preach from) On the back, add a hinge to attach to like a small table top to your podium, attach the other half of the hinge to that. Now you have a podium with a top on it, and a hinge on the back, right? Now cut yourself a little wedge, couple a 45's will do. Now when you want to sharpen a tool, slide your lil podium up to your grinder, look for what angle you need, push the wedge between the top you made and the top of the podium till it matches the angle of your tool.
Note: this works best if your sharpening stand (podium)and your grinder are attached to the same piece a wood, bench, what ever.