I happened upon this inspiring Artists Network post on Ten Art Projects to Fuel Your Creativity written by Courtney Jordan. Below, are just a few of her ideas:
"Pick ONE Color and Fill a Page: For, example, cover the page with objects outlined in black pen or marker and filled in with color (colored pencil, marker, watercolor, collage papers...Discover how many red, blue, green OR purple things you can think of and how creative you can be when it comes to incorporating your chosen color. Put them all together in an artful collage, and then fill them in with the ONE color that unites them all."
"Favorites Grid:" Jordan borrowed this idea from Danny Gregory and she suggests using a sketchbook for the grid. Jordan says, "Start by thinking of your favorite breakfast foods, cars, book characters, hats, footwear or type of flower. Make a grid in your sketchbook. Lines of neat boxes outlined in black marker that are waiting to be filled. Now draw a small thumbnail sketch in each box according to the chosen theme.
"Make an Abstract Painting: Is it something you do often or have never done before? Working abstract is great as a warm up with big, unhindered gestures and lots of movement in and around your surface. It can also lead you to discover something about combining materials, unusual marks and effects; realism doesn’t have to be your aim."
Check out the rest of the article for more ideas.