In the double boiler, melt your waxes and oil together.
Once melted, remove from heat and add your essential oils. Stir well.
Line up the lip balm tubes on a level surface. Pour the melted wax into each tube, only filling halfway. This prevents a hole from forming up top.
Once the lip balm has cooled, reheat the remaining oils and top up the rest of the tube.
If the top cools unevenly, use a heat gun or lighter to level the top. Careful not to melt the tube!
Notes
A double boiler with a pour spout makes it easy to pour into the small lip balm tubes. If you don't have one, transfer the hot liquid into a measuring cup or other container with a spout to make pouring easier.