Answer:
Variety
Step-by-step explanation:
Everyone has a bit of a dfferently shaped fae. You can go by their backgrounds when deciding their head shape. Maybe it's from a family member, their race, etc. When decideding things like this, it's good to start with a rough draft to figure out how you want to form the face. I usually divide the face into sections with horizontal lines going across. Make sure the face shape allows room for the eyes, nose, and lips without them being squished or spread apart too far. The ears are usually near the eye level, but it may vary. Starting with shapes in pencil and then using pen to connect them is a good way to start. Remember, you don't have to make it perfect. Eyes are not the same exact shape.