Keep your eyes closed. Now draw.

Okay, it wasn't really as dramatic as that.  But, we were asked to only look at a photo and never look at our paper while we were sketching.  We were practicing contour sketches which is a type of drawing that works on hand-eye coordination.  The goal was to never let our pens leave the page and keep our eyes focused only on the screen. 
Now, you may think what I'm about to show you looks like a 5 year-old's proudest new drawing brought home to show their mommy and daddy and that's probably not so far off.  However, you try and never look at your drawing and see what you come up with!

I'll show the picture we were given first, and then my sketch...

I really like doing these drawings because it helps me practice my hand-eye coordination and become a better sketcher.  When we only have time to do a very quick sketch of a place to get an idea down on paper, we may not have enough time to look down, so this type of idea expression is worth taking whatever small amount of time you do have to do.