Okay, let's see with examples.
You want curly hair. I'm sure as hell you [as almost every other artist] are even a bit lazy. You don't want to make curl by curl. You want only the baby, not the labor pains. How to make something that hard? Simple.
First off, you star by making the original shape of the hair covering the head, pretty much in the form of Elan's hair. Next, you switch the fill color to black [in case you want it black]. Now, you take the freeform pencil, and start making little spirals going
OVER the original outside of the hair. You switch the thickness of the line and everything.
Voilą!
The example, you say?
Why, here it is:
look at the hair, you'll see the way the hair is just a spiral going about the head.
EDIT:
What? You say it's too small to see?
Well, here's an example, for both the "rectangle" question and yours!