There are so many possibilities it can freeze you right in your tracks. That's why art journaling aficionados often recommend filling the blank page with paint, paper collage, or even scribbles, just to get something down and make that blank space less fearsome.
Another way you can "brainstorm on paper" is to use a substrate with a built-in texture, pattern, or image. Even if you end up covering the whole thing up, it fills in that first frightening step.
Here are some of my favorite starter substrates, taken from past issues of Cloth Paper Scissors. Some you are probably familiar with. Some might surprise you.
Textured mat board (Fall 2006). Discarded pieces of embossed and textured mat board from her frame shop led Terri Haugen to find a new use for them. She discovered they are perfect as "jumpstart backgrounds" for collages and artist trading cards. You can paint the board, apply matte medium, sculpt or imprint using molding paste and rubber stamps, lightly sand to alter the colors or reveal more texture, and so on.
Cabinet cards (Summer 2006). Victorian cabinet cards, 4" x 6" pressboard-backed photos of a person or a family, are perfect for stimulating a "story," because the subject or focal point is already provided. Maija Lepore shows how to mask off the image and create a background around it, adding embellishments on top of the image afterward.
Vintage postcards (Winter 2006). Using vintage scenic postcards as a base gives you an instant backdrop for collage, journaling, or mail art, as Diane Downs shows. You can put your focal point on the beach at Waikiki, in Rome's coliseum, or outside a stately English manor using small images, rubber stamps, transparencies, and embellishments. Diane also suggests you use the address side of old postcards where beautiful handwriting and interesting postage stamps and postmarks can often be found.
Book covers (Spring 2006). Old hardcover books have many wonderful built-in features, according to artist Roben-Marie Smith. The textured fabric on them can be lightly sanded and painted for extra interest and it tears and frays along the edges for a nice effect. They are sturdy enough for mailing as a postcard, too. One of Roben-Marie's many tips: choose dictionaries, shorthand books, and other language books as their pages make terrific collage papers.
Participate in a round robin (Summer 2006). OK, so the first step in a round robin mixed-media collage does confront you with a blank slate. But after that, you get as many opportunities to embellish upon someone else's artwork as there are participants in the exchange. As Pokey Bolton shared about the round robin she participated in, the experience is a great way to see art, techniques, and tools from a completely different perspective.
That's five ideas, just from the 2006 issues. Alas, these issues are no longer in print. But if you hurry, you can get them in a Collection CD for 20% off, along with all the 2007 issues. The Collection CDs for 2004-2005 and 2008 are on sale now, too.