I discovered this delightful craft a few weeks ago and now I am addicted to making and using them. It's fun to mix and match glitters and water colorings, and also to add trinkets to the bottles! The ones I have contain confetti stars, blue/green water and gold, blue and green glitter in it. My other one has pink and silver glitter and plastic jewels.
They are also known as Time Out bottles, Hush bottles, and Glitter bottles. Look for other various instructions on how to make these, as each one holds their own merits.