They aren't cheap but what I use are three flute aircraft aluminum countersinks or carbide countersinks. I have one each of the aircraft ones for SAE and Metric. I use the carbide tools for carbon fiber and also for plastics where the 3-flute seems to not give as smooth a cut as it does on aluminum.
Quite honestly, the only way to get a good countersunk hole is to have the workpiece clamped down firmly and a limit stop on the tool held in a drill press or a milling machine. Doing it with a countersink cutter in a hand held too always results in bit chatter. A grinding bit won't chatter but also will not give a good finish and is unlikely to give a proper profile cut.