I really enjoy making bottles like this for my kids. Not only are they beautiful but they make great center pieces for dinner that night and breakfast the next morning. :)
This bottle we added water and flowers form our garden. It was really neat seeing how the water reflected off of some of the flowers, and was a nice way to go over colors, plant parts, and counting.
I suggest if you do this not to glue the lid close unless really needed after a few days our water become yellow and was no longer interesting to my kids when it did. You can reuse the bottle for another craft if not glued on.