Cut 6 small pieces of wax paper or parchment paper for wrapping the bath bombs.

In a medium bowl, mix the baking soda, citric acid, and dry milk powder. If there are any clumps, break them up.

In a small bowl, melt the shea butter (either in the microwave for a few seconds or in a double boiler)

Add the lavender essential oil to the melted shea butter

Slowly pour the shea butter mixture into the dry mixture and mix well

You should start to notice that the mixture will start to stick together.

When you think the shea butter is mixed throughout, squeeze the mixture in your hand to see if it will stick together.

If it's not sticking together well, spritz it with witch hazel. Just one squirt at a time as too much moisture will cause the baking soda and citric acid to start reacting.

Pack the mixture into the bath bomb mold. I just use a 1/2 cup measuring cup. I find this is the easiest way to form them and get them out.

If you want to have some dried herbs for decorations on the outside of the bath bomb, put a bit in the mold before packing the bath bomb mixture in it.

Once the mixture is packed tightly, turn it out onto a piece of wax paper or parchment paper.

Allow the bath bombs to dry for several hours.

Wrap the bath bomb in wax or parchment paper and use twine or string to tie closed.

Store bath bombs in an air tight jar.