Not all herbs are suitable for making tea, so become informed on each particular herb before ingesting a tea made from it.
The steps involved in making both enjoyable beverages and medicinal teas are pretty much the same. The major difference is that when making medicinal teas, more attention should be paid to covering the water pot as much as possible to entrap the beneficial properties of the herb. While the aroma of the tea is part of the enjoyment for making beverages, there should be no aroma when making teas for medicinal uses.
Having said that, making a pot of herbal tea is actually an easy thing to do. Bring cool water to a boil, and then rinse a non-metal container with some of the water. (Metal containers can interfere with the purity of the tea). Add 2 tablespoons of fresh, or 1 tablespoon of dried herb (or crushed seed) to the pot for each cup of water, plus an extra 2 tablespoons of fresh or 1 tablespoon of dried "for the pot." (For iced tea, increase to 3 tablespoons of fresh and 2 tablespoons of dried herb to allow for watering down by melting ice).
Therefore, if making 2 cups of hot tea, you would use 6 tablespoons of fresh herb or 3 tablespoons of dried.
Put the herbs in the non-metal pot, and pour the boiling water over the herbs. Let them steep, covered, for about 5 minutes. This is not an exact time, and you should check at varying intervals to find the right strength for your purposes. Strain the herbs out of the water when the desired strength is reached.