Here is what I made for under $15:
Most of it came from Hobby Lobby.
- Fabric, 45" width, 3 yards @ 2.99/yard.
- Acrylic hobby paints @ .70 per: White, red, yellow, light blue.
- Plastic compartment palette (optional) @ $1.
- Toothbrush, use an old one or get one from dollar store.
Just lay out the cloth on a surface where you can make a little mess. Squirt out a little paint onto the palette and load up the toothbrush bristles with paint, then hold it over the fabric and drag your thumb across the bristles to spray paint dots. More paint on the brush equals larger dots.
I did mostly white and mixed in some yellow, red, and light blue to give a little variety.