I set up a makeshift double boiler by setting a glass bowl over a pot of water at a low boil.
Add the beeswax, shea butter, and coconut oil to the bowl. The beeswax may take longer to melt, but be patient. ;)
Stir the oils and beeswax frequently until melted.
Remove from heat.
Add the zinc oxide and stir together until smooth.
I added about 10 drops of lavender essential oil to mine, but feel free to leave this step out completely. Note: not all essential oils are safe for use in the sun, please do your research if you choose to add them to a sunscreen.
Pour mixture into a glass container that you can seal with a lid and let cool.