Well you can use this to help with your entries in the photorealism competition. Oh and im using the java tool. Enjoy, :)
Im just naming the tools that are gonna be used for the people who dont know where they are.
This is what the result will be when you're done :D
First, sketch out the look of the hair. It Does NOT have to be a realistic sketch, its only a guide.
ignore the part of the hair that is already drawn. Now look at the part that is circled. Fill in your sketch with Black, no matter what color your hair shall be, the base color is black.
Now, Zoom in twice. now draw each strand of hair with a drak version of the hairs real color. Now if you have a dark computer, you wont be able to see the the dark brown strands I drew; That's okay. and dont forget, each type of hair has a style, straight, curly, messy etc. mine is curly-ish ._. and i circled what each strand looks like
Now, right over the dark color, get an even lighter version of your hair color. dont forget AIRBRUSH: SIZE-1 OCAPACITY-255. now draw not as many but enough lighter hair strands. I circled the tip of the hair, so draw MANY strands of hair at your tip.
Now, add very light strands of your color over the others, and you're done! If you ever thing an area of your hair is too dark, take the lighten tool and fix it, if its too light, take the darken tool and fix it.
dont forget to zoom out. with the "100% zoom" tool.