What are the procedures in making medicine

There are 2 different ways of preparing a tea:

Infusions are made by pouring hot or boiling water on the herbs and steeping for a period of time usually 20 to 45 minutes, commercially prepared tea bags are grounded fine to make tea faster, in about 5 minutes.

Cold infusions are made by placing herbs in cold water and letting them sit for about 8 hours, this method is used when the herbs are sensitive to heat or loose their essential oil when heated.

DECOCTIONS

Whenever the herb to be used is hard and woody, it is better to make a decoction rather than an infusion or tea, to ensure that the soluble contents of the herbs actually reach the water. Since many herb preparations consist in using bark, roots, wood, nuts, and seeds, it is necessary to boil the herb and more heat has to be used, in order to get through the hard and strong walls of these herbs.

Decoctions are prepared by simmering the herbs for 30 minutes or longer. The high temperature over a long period of time releases more properties from thick barks and roots, remember to keep the heat low and cover the saucepan in order to keep the essential properties inside and to avoid too much evaporation.

If the recipe you are making calls for the use of soft and hard herbs, I recommend to make a decoction and an infusion separately, then combine the two liquids. This way the sensitive properties of the soft herb remain intact, and the hard to get properties from the hard herb is collected as well. However, if the hard herb contains oil, it is best to powder it and then use in an infusion, rather than a decoction, to ensure that the volatile oil does not evaporate.