Go someplace where you normally would never do something creative and work there today.
I usually start work at 8am, but on those rare days where I have a later start (like today!), I like to stop by the grocery store (which incidentally opens at 8) on my morning walk to work and pick up an apple or something to complement my lunch. So what better place to attempt a creative assignment? The store was very quiet, and I walked around a bit first, looking at products on shelves and hoping for ideas. I settled on making a pattern of sorts by rotating tuna cans... It's a bit subtle, but I was also working quickly in hopes of avoiding being 'caught' by an employee or other customer. I left the pattern behind, paid for my apple and went on my way.