Which proportions belong in an outline comparison?

For an upcoming paper mask workshop, I want the planning stage to account for the different outlines of participants’ faces. A generic template is convenient, but its outline does not tell us where an individual mask may need extra room. I am considering a short explanation of face shapes as background for that worksheet. My intention is to use the categories for describing contours, then measure each participant rather than infer sizes from a label. We could note the widest part of the face and the jaw outline before deciding which template edges to redraw. The paper versions will be tested before decoration, leaving time to change the edges without wasting paint or other materials. I also want participants to feel free to disagree with a label if another description better matches their own observations. The finished design can still be exaggerated for a character; the preliminary notes are simply there to guide the first fitting. What would you include on that planning sheet to make the first fitting easier without turning the workshop into a classification lesson?