Here’s my first go at a skull. I think it’s pretty good no? at least for a first attempt 
I’m not really that good with lighting and scenes yet.
and yes i am aware that there are a couple too many teeth up top lol. at least i think there are.
suggestions gladly welcome. 
I think the cheek and so are good but the back head looks weird, but it’s good for first try.
maybe it’s just because of the angle. I have really good refference images so the proportions are correct. though to admit the back is messed up, but im getting there. ill get a few more angles
Teeth: 16 upper and lower in an adult. 12 upper and lower in a child. Hope that helps.
I agree about the teeth, even if you use a different number of them they may look better if they are closer to the correct proportional sizes.