Well, start on the face using a variation of gray tones to mark the shadows and limits of the face, beginning to highlight the most important features, with the help of a black color delineate the part of the eye and darken some gray shadows, stroke I mark the eyebrows with the same color, avoiding the areas that would be of other colors, that is to say not to go over the lines so to speak.

I've always been messy when drawing as you see now I started with the hair, it cost me a bit to find the right color for this reddish hair but little by little I was shaping it, with a base shading layer place the yellow and red oranges on it giving the sensation of direction in each hair or strand.

Here I began to place a base of light skin color over the entire face and then little by little with a darker skin tone paint over the shadow areas giving it the necessary volume.

Here you can see the final result of these pink shades that you place on the base giving a bit more darkness to the face shading with softness and firmness.

I then proceeded with the rest of the hair, if you look closely at the drawing you can see the color tests that you do on the side of the sheet, in order to find a tone that looks good in this composition, it is always valid to try on a sheet to part how will be the mixture of our colors to avoid future mistakes.

Here I began with the help of a sharpie alcohol marker Gray color the base of the lines of the print of his clothes, as the end result was a dark tone the gray marker helps to leave a more homogeneous finish when placing the color.

Apart from that gray base, put a blue base also, remember that neither the totally black color exists in the drawings since it is a very strong color to be totally pure therefore mixing it with another dark color is not too much, in this case Use a purple blue color for this.

And we would get this result in the print, then proceeded to start with the other side of the hair placing a base of gray and black lines to identify the place where the shadows would go and show the movement that would follow the girl's hair.

After that it only remains to play with the mixture of colors we use on the other side of the hair, yellows, oranges, reds and reddish brown to give this effect, I am left a darker tone than the original image but be satisfied with the result that I got to have so much time without drawing the drawing, in my opinion it looks very good, here in the next two images you can see the reference image and the finished drawing in comparison.