Anatomy basic shapes - most people know of these simple drawing rules. But when you are having fun drawing you somehow ignore them, or maybe thats just me? Anyways, i beleive using them more consistently would improve my drawings a lot!
"How to Draw Hair tutorial by =ribkaDory on deviantART: by drawing the ends and hairs at hairline close together you can create shading and a sense of form. This will help if you are into drawing people.