Harvest plant material right before beginning the distillation process, to ensure it is at its freshest. Plants that sit after harvesting and before extracting essential oils can become desiccated and some of the essential oils can evaporate.
Fill the still approximately half full with plain water.
Place plant materials in the "steam" basket of the still. The steam basket sits above the liquid, similar to a kitchen steamer for vegetables. Fill the steamer with the plant materials but do not pack them in tightly.
Place a receptacle under the outlet valve of the still to catch and hold the resulting liquid, which is a mixture of water and distilled plant oil. The oil will rise to the top and you can skim it off and separate it from the distilling water.
Put the still together, following the directions and procedures relative to your particular model.
Turn on the heat source. Allow the still to extract the oil from the plant materials.