This patriotic craft was cheap and fun. I went to Lowes and had them cut a 3x3 board in pieces for me. The biggest firework is 16", then 12", 8" and 4". I just spray painted them and added a little embellishing with some scrapbook paper and ribbon I had.
Make a small hole (for fuse) in the top with a sharp tool ( I just used sharp scissors).
For the fuse, wrap wire around a pencil to curl it, and stick it in the top.
Big enough that they stand out, yet small enough that they are easy to store. You could also do bigger ones for outside.