This is the first pixel artwork I've created so I'm still very green. I'm not entirely sure what advice I need so I won't try to preempt you but I will say you can ignore the feet as I haven't bothered to detail them.
When I started I wanted to recreate, or at least borrow from, Seiken Densetsu 3 style of character art. Most online tutorials seem to discuss the subtle tiling of the environments but I haven't really found anywhere discussing the quite contrasted and heavily highlighted character art:
I think I've had some moderate success in the hair but whenever I tried to use the method of highlighting seen in the SD3 artwork I really struggled to stop the brighter areas from sticking out too much. I ended up doing something quite different with the highlights as you can see.