Harvest young, thin rosemary sprigs (or other herbs) from your garden. Press them flat. This can be done by leaving them in between heavy books until totally dry.
Cut the sprigs to they will sit 1" below the jar's rim.
Measure out your essential oils into a glass container. You'll need 6 ml of fir oil, 4 ml of bergamot, 4 ml cedarwood, and 1 ml of juniper berry essential oil. Set aside.
Create a double boiler and melt the wax completely. As the wax is melting, use tongs to dip the rosemary into melted wax and then "glue" them to the inside of the mason jar. Use a craft paintbrush to add additional melted wax to help keep the herbs in place.
Next, cut your wick to go just over the mason jar lip. Use pliers to attach a metal tab, then add a glue dot at the bottom to center the wix. Clothespins can be used to keep the wick centered and secured.
Once the wax is fully melted, remove it from heat and stir in the essential oils using a popsicle stick. Then divide out the wax mixture and pour it into each prepared jar. Allow the wax to harden fully for about 48 hours.