If you're looking for something cute and creative, but you're fresh out of ideas, How Does She has some really fun printable projects. Just subscribe to the newsletter (see the pink box at the bottom of her blog page) and you'll receive the password for the downloads.
At the top of the list, you'll find some back to school printables. If you're like me, you take pictures on the first day of school. Just print the appropriate sign for your child's grade and have him or her hold it in the picture.
Here is an example from How Does She:
And don't forget to scroll down through the seasonal downloads to the other school download for some cute lunchbox notes you can print. All designs have been created by Chickabug for How Does She.