sure, ill try to explain how i do those. anyways, assuming youre using adobe illustrator, pick a small brush and draw an outline about the thickness of a pencil to start out with. then on the pallete window at the bottom theres these icons that are two boxes overlapping each other. make sure the second one is highlighted. then below that is a row of three little boxes. click the third one. once you get that, go back up to the two icons and pick the first one. then click the first box in the row of three and pick the color black. and there you have it.
hopefully that made sense.