1. Get cheap vases at thrift stores. I look for the 50% off ones especially.
2. After figuring out how to stack them (I like to do them mostly upside down if I can), use E6000 adhesive to secure them together and then weight the top with books. Only do one section at a time.
3. Glue a shallow plate to the top (2" deep or less or the birds won't like it.) I put one on the bottom as well, upside down, for extra stabilization. I cover it with dirt and rocks when I put it outside.
4. After letting the two separate sections dry overnight, glue them together and let that part dry overnight. Then put them outside, add water or birdseed, and wait for the birds.