Ok first of all let me tell you that you rock!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Love the lines and the firmness of your strokes.
So why dont you try making a 512 tb head drawn in pencil?
Should be interesting
Here it is
if you're new to photoshop, treat it like paper, but take more liberties with experimenting.
its photoshop, you dont have to get it right first time.
spam layers, dont be afraid to get messy, mess with opacities, draw a shit tonne.
draw the big picture in first and refine, rather than start on the small details and build up.