Michaels arts and crafs has a book in detail about this and also type your question into google and i think their is something on you tube.

Aromatherapy candles are made much the same as regular candles. They can be made in a mold but there is an easier way. Make the candle in a container such as a tin, jar or other fireproof vessel. This method requires a wick or two or three, depending on the size of your vessel.

The wick must be secured at the bottom of the vessel and also at the top of the vessel until the hot wax is poured and then cooled. The wick will move in the pouring and cooling process if it is not anchored, or secured in the position wanted.

The wax is melted in a double boiler, therapeutic essential oils are added to the wax and when the wax is pourable it is carefully poured into the wicked vessel. When the wax has cooled additional wax is added to the top to cap it off. This is done because the wax will shrink as it cools leaving a concave pocket around the wick.

Wax should never be left unattended during the melting process. A good work surface should be covered to protect from wax spills and essential oil spills. Both can cause damage to work surfaces. Always read complete directions on the packaging of essential oils and bulk candle wax.