Here is probably the most simple sensory bottle to make. (This also happens to be my favorite toy to make just because it involves glitter!) Simply grab a water bottle, add glitter, and shake the bottle until a tornado appears. It's so exciting for babies to observe the glitter spin around and finally settle to the bottom of the bottle. We do this over and over again when my baby girl is sitting in her high chair eating. This is so inexpensive and just so easy to create!