<Postcards> Design the front and back of one page in your journal so that it looks like a postcard... the "message" side will have a vertical line down the middle, a faux stamp, address, message, etc. while the "picture" side will have mostly imagery.
<TV Guide> Use the Random TV Show Pitch Generator to develop the theme for your page.
<Powerpoint Nightmare> Structure your page like a corporate powerpoint presentation, with tacky bulleted format and perhaps some graphs. The trick - the topic should be something most definitely inappropriate for any workplace!!!
<Spiralicious> Make a little star or flower in the middle of your page, and start writing from that icon outword in a larger and larger spiral, turning your page as you go. Draw a guideline if you wish, or write freehand. Practice a font or change fonts.
<Idea Preserves> Instead of raspberry jam, preserve ideas using imaginary jars. Sketch the jars on your art journal page and fill them with ideas on a subject of your choosing. Things you want to learn more about, your worries, your favorite foods. The photo of colorful jars was taken at the Pittsburgh Children's Museum (a wonderful spot, if you have the chance to visit).
<Scrap-cycle> Make a page that looks like a bicycle, just kidding (checking if anyone is reading these prompts)... the idea is to cut some scrap, unused, recycle-ready scrapbook paper and patterned cardstock into 1"x1" squares (inchies) and use these to build a collage. This can be your background or the focus of the page. There is a lovely inchie quilt at Oh, Fransson.
Check out the entire series of prompts to Kick-Start Your Art Journal!