Here is a great sketch by Tina Wilson. She's a friend of mine...to see more of her sketches, check out her blog http://seemssketchy.blogspot.com/
Sketches are a super starting point...and provide lots of inspiration. You can completly lift the sketch or maybe even just take a few points from it. It's sometimes amazing to see how the layout ends up when you start with a sketch. Sometimes it looks nothing like what you started with.
One thing you should always try to do , is give the sketch artist credit when you use one of their sketches.
Have fun with it, and be sure to post your creation in the Kindred Creations gallery!!!!