When shaping gravers on a grinding wheel take your time. Hurrying will only cause the graver to overheat and/or cutting edges to be misalign.
Always grind a graver with the cutting edge of the graver making first contact. As a grinding wheel grinds away metal heat is generated. If the wheel grinds from the heavy portion of the graver first, heat is generated towards the tip. By grinding the cutting edge first, heat is generated away from the thin tip of the graver. The difference is minimal; however, when shaping gravers every little bit helps.