For this exercise you will need some permanent ink and crayons.  I use Sumi Ink and my water soluble art crayons.  I used an image from a catalog and loosely sketched it out with the Sumi ink. Once the ink was dry I started coloring in the image with crayons.   I love how the ink and crayons work so well together.  Once the ink has dried  and you have added a layer of crayon you can use water to move the crayons around as you would a watercolor paint.  

I added bold colors at the end to give this piece more energy.  To me she has an Amy Winehouse-ness to her.  

If you travel a lot this would be a great lesson to take with you.  You could fill a journal with a bunch of ink drawing that you could paint later with crayons.