I went a bit nuts making more banners for Cindy Lou's birthday party last month. I got carried away cutting triangles from just about every possible fabric in my stash, and ended up having to buy about 10 additional packages of bias tape. I made four more Fourth of July banners, and I was amazed at how well the other fabrics ended up falling into pretty neat categories. That way each banner would just have four to eight different fabrics in it, instead of 20. When I first starting making them, I was certain that I would end up giving a large number of them away as gifts. Once I had them all hung in the dining room, however, I wasn't sure I would be willing to part with any of them--it was like being in a circus tent.
One small note about cutting and construction: when you're folding over a piece of fabric for mass triangle cutting, make sure the first fold leaves the fabric with right sides out. That way when you're dividing your cut stack into pairs of triangles, they will already have wrong sides together, ready for stitching.