Baby shower idea: Guess the baby's birthday! Great way to replace a guest book. You could use stickers of a pacifier and/or a rattle. Each person placed the sticker on the date they predicted and signed their name. Perfect to put in a scrapbook, too!
If you're doing a project that requires a lot of tissue paper (making paper flowers for your wedding, for example), buying bulk tissue paper is the way to go. Here are my favorite go-to resources for bulk tissue paper.