I made these ruffled streamers from crepe paper for Elise's party after seeing the idea here. This is a super easy, cheap and quick way to make custom party decorations. There's really no way to mess it up since it looks better the messier it is.
Start with a few different colors of crepe paper. (I used three.) Cut the paper into 12-18" lengths. They don't need to be exact and they don't need to be the same. Just estimate.
Take two strips and layer them.
Begin sewing and push the paper underneath the presser foot. The more you bunch it up the more ruffled it will look.
If the two layers start to slide apart, or your stiching veers off the center, that's OK. Keep sewing and gently guide your stitching in the right direction. Once I got the hang of it, I sewed really fast, which sort of eliminated the desire to make everything straight and perfect.
Keep layering in new pieces and sewing them into one giant piece. You can easily cut the streamer later without any unraveling.
Kind of impossible to get a decent photo of how they look hanging up.