I tune the drum shells to themselves. Just knock on the middle of the shell and start emulating the tone using the reso side first, then the batter. Tuning a drum to itself is the beginning then you can listen for raising or lowering them to have a balance and coordination in pitches from tom to tom. This is the correct way to tune an acoustic drum and again use suttle chances to ehhance the kit. If your looking to get crazy you can go orchestral and tune to Concert C but I prefer using the individual drums properties to get the best that the drum can produce. Been doing it this way for a long time and my drums always sound great, and the folks always comment on that too. Doc