I grade in this order (each out of 10)

Posture
Hand Position
Foot Tap
Breathing/Blowing (Air)
Tonguing
Pitch (not tuning)
Rhythm
Tone Quality

I can raise or lower any of the above to place (or remove) emphasis from that particular part of playing.

I use an excel spreadsheet that adds the scores in real time AND sorts the class by chair order based upon who scores the highest. If there is a tie, the best tone quality score is the tie breaker.

This has worked very well for me.

Jeremy