Fill your mason jar 1/4th of the way with water. Add a generous amount of glitter to the water. Squeeze your first color of paint into the jar. We kind of did a circle swirl.
Put the lid on the jar tight and shake- Mixing the color and glitter together.
Remove lid and use the cotton balls, stretched out thin, in the jar. We used craft sticks to maneuver the cotton to the edges. Be careful not to press the cotton into the jar. You want it to be loose versus compacted.
Once the cotton soaks up the majority of the water, fill the jar about 1/3rd of the way with more water. Add your next color and a little more glitter if you desire. I grabbed the mouth of the jar a few times and twisted it, kind of spinning it a little to get the color to mix.
Add more stretched out cotton balls to the new color water. Continue to repeat these steps until you reach the top of the jar.
Finish the top with cotton balls, do not compact down. Screw on the lid. (Optional- we tipped our jars upside down to mix it and spun them in circles. You do not have to do this but it is pretty neat to see it all mix)