Place the shea butter or other solid oil in the top of a double boiler (or stainless steel bowl set on top of a saucepan full of water) over low heat. Heat until just melted. If using a liquid oil, you can skip this step.
When melted, carefully remove the pan from the heat.
Allow mixture to cool for about 5 minutes so that it's still liquid, but not as warm. This will allow you to blend the essential oils into the mixture without damaging the oils' healing qualities.
If using beeswax, stir into the rub after removing from heat.
Add essential oils to the carrier oil. Blend well.
Pour blend into a small glass jar.
To use, rub mixture on chest.
Store closed jar in a dark, cool place for up to 1 year.