The hair line should not be too straight, otherwise it will look ugly and look like an afro. It should be slightly curved, like the kind that has been blown by the wind. The eyes should not be too flat. I have done it several times. Fox eyes (dizzy), if you want to draw the back, you must remember that the hem of the cloak should not exceed half of the calf.
Actually, I am also a fan of the fourth generation. I hope you can draw a super cool painting.
Finally, a reminder, it is best to have some meaning when drawing, for example, draw Naruto, Sasuke and his son, etc. It is absolutely my own creation, hope you will adopt it!