You can do your own thing, or if you need more direction, you can follow what we did.
At first I gave my daughter the challenge like stated above. She had a very hard time with it. She tried to do it by drawing the outline of a flower with a dotted line, but she got frustrated when it didn't look perfect. So the next day I pulled out my book on Vincent Van Gogh. We looked at the drawings and paintings, and I asked her to point out where she saw lines and to look at how he painted or drew with just lines. His ability to draw and paint with just lines is incredible! After looking at the examples, she understood.