Source: A Druid's Herbal, by Ellen Evert Hopman

Herbs that are useful for skin conditions (such as comfrey, lavendar, calendula, pine needles aloes, etc.) can be made into salves. The ideal time to make a salve is in midsummer when the herbs are fresh and abundant, but dried herbs can be used as well. Consider adding green walnut hulls and whole, smashed horse chestnuts to the basic mix for their skin- healing and painkiller properties.

Simmer herbs in good quality olive oil in a large pot. In a separate pot, melt and simmer three to four tablespoons of fresh beeswax (the beeswax should be golden and have a strong honey scent) per cup of oil. Put enough oil in the pot to just cover the herbs. Simmer the herbs in the oil for about twenty minutes. When wax and oil reach the same approximate temperature, pour in the wax. Strain and pour into clean sanitary airtight jars. Tincture of benzoin (about one oz per quart) may be added as a preservative while the salve is still liquid although this is not strictly necessary. The most important factor in controlling mold is to have immaculately clean and dry jars and utensils. Boiling followed by thorough drying is all that is usually needed. Persons living in very hot and damp climates may want to take extra precaution of adding the tincture of benzoin.