Star paper is another thing you can stack up on. If you were dedicated, you could probably cut your own star paper using a cutting mat, but due to the size of it, I find it quite tedious. I prefer to buy the packs from shops. You can usually find them as Asian specialist stores. In particular, I found these ones at a Japanese figurine import store, haha.
The largest star jar that I had available just so happened to be the shape of a star too, hehe. You like stars? Here’s stars in a star! XD I tied an organza ribbon to the neck of the jar.