If you like to get funky and use fabrics,
here is a fun way to do painted fabric.
Choose an acrylic paint and add approximately a tablespoon to a plastic zip bag and smoosh it around, you may add a tablespoon of water too. Then wet a piece of fabric, 1/8 to 1/4 yard - any scrap will do. Canvas, muslin, cheesecloth, cottons all work fine. Place the wet fabric into the bag and shake it around. Remove and see if it's as you like it, if not replace and shake more. (You can also use another bag with a different color too)
When you are satisfied, remove from the bag and lay flat on waxed paper to dry. Now you have a custom piece of fabric to incorporate into your projects, use as a base, cut it up or whatever!