If you can paint as well as you can draw, the rest of us are going to look like ass!
If you want to do fades w/o an airbrush, there are some things you can try. For example, take a piece of thin cardboard and cut little slots in it the same shape and size of the approximate areas that you want to mist. Then hold it over where they go on the body. Keep it a couple inches off the body and then lightly spray over it. That'll give you a misted look without the real hard edges. The amount of blur will depend on how far you hold it from the body and how heavy you throw the paint at it. Might want to practice a little before throwing it on the body.