I am a child/adolescent therapist and these "calm bottles" are a fun intervention primarily used for emotional regulation. For more activities visit Creative Clinical Social Worker.

Goals: Decreasing anxiety, fear, self-harming behaviors, etc.; Anger management; Expressive/physical release

Step 1: Supplies

Container: This is typically made with a glass mason jar, but since I often make these with children I use water bottles with smooth sides.
One bottle of clear glue (not white glue that dries clear), or glitter glue: I like using regular glue so I don’t have to deal with the hot water since I make these in my office. Glue/glitter glue works best, but you could also use corn syrup if that’s all you have. You have to pour it directly in the water without letting it touch the sides of the bottle or the glitter will stick to it.
Water: It can be room temperature if you use regular glue but should be hot (I use boiling water) if glitter glue is used. If the water is not hot enough then the glitter will become clumpy and separate.
Glitter: I use mostly super fine glitter with a little regular sized. I sometimes add sequins, beads, shells, plastic jewels, etc. Glow in the dark glitter looks really cool if you can find it. Less (or even none) is needed with glitter glue bottles
Food coloring: This is optional. Only use one drop or it becomes difficult to see the glitter.
Strong glue or duct tape: This is used to fasten the lid to the container. I like using colored duct tape.

Step 2: Directions

Making a Calm Bottle (clear glue): Fill the bottle 3/4 of the way full with water. Then add the glue (and shake) and glitter (and shake). I use a funnel for the glitter. The more glue you use, the longer it will take the glitter to fall. I usually use the whole bottle. Add 1 drop of food coloring, if desired, and then glue/tape the lid on.

Making a Calm Bottle (glitter glue): Instead of clear glue you can use glitter glue. If you go this rout then mix the glitter glue in a bowl with very hot water (I boil the water) before adding it to the bottle. If the water is not hot enough then the glue will clump up and not work. You can add 1 drop of food color and additional glitter is desired.

Step 3: Using the Calm Bottle

When your client (or child or yourself) becomes upset, angry, frustrated, anxious, etc., direct them to shake the bottle vigorously as long as they want as an expressive/physical release activity. When they are finished they set the bottle down and watch the glitter fall as they use their favorite coping tool and/or deep breathing exercise (how to teach deep breathing can be found here).
Other uses: This is a common coping tool used for people who self-harm and is easily adaptable to many clinical issues. I have also used this as a coping tool + timer for kids who are transitioning into sleeping in their own bed or have trouble focusing and are taking long breaks during homework. Some parents use them in place of "time-outs" when children become dysregulated. It is a highly adaptable to numerous therapeutic goals. You can also make these just because they are awesome and fun to make, or as an art project :)