Here is a rough sketch of the measurements I'll need for the Padme "Packing Gown" headpiece/jewelry and armbands (click on image for larger view):
For the headpiece, I'll need a measurement from point A (just above the ear) to point B (center of forehead at hairline). I'll also need a measurement from point A to point C across the top of the head (lying flat against the hair).
For the armbands, you need to determine where each of the 4 bands will be positioned on your arm and take 4 measurements, D, E, F, & G, over the shirt preferably. If each of your arms is significantly different than the other, you should take each measurement for both arms.