Hello! I recommend finding a good reference; it will really help keep you on the right track. Adding some saturation and contrast would benefit the image. Also, I find that hair is easier to paint if you break it down into large shapes first—this helps you grasp the overall volume before diving into the finer details. And for the finishing touches, try adding some floating debris in the environment; it always brings a sense of dynamism to a drawing. I hope this helps!