Here's a real quick banner idea... it's actually from last year. I had just finished going through my Halloween stash and I wanted to make something quick to hang up. At that time I had a stack of black chipboard, so I cut it into triangles and got to work cutting up patterned paper. Didn't really try to match anything- I liked the randomness of color and design.
Everything is strung with a narrow black satin ribbon but I tied pieces of coordinating ribbons in between each 'flag'. So far, so good. Roaming the aisles at Michael's looking for something to hang from each point I ran across some smoky black beads. I grabbed a package of earring wires and got to work attaching the two together. To reinforce the hole at the point, I used eyelets.