Herbal medicine making is an ancient and not very difficult undertaking. In the do-it-yourself realm, nothing is simpler than an herbal tea or infusion. These can be mildly beneficial as for instance with a post digestive tea with some nice warm aromatic spices or perhaps a gentle nervine to promote relaxation and better sleep. However, some teas have more profound effects, such as my lymphatic teas that support digestion, elimination, and lymphatic movement. Other teas, especially those used in traditional Chinese medicine, can be very strong but less pleasant to the taste buds.
Many herbs that are easily grown make nice teas: mint, lemongrass, hyssop, thyme, chamomile, and so on and so forth. Some of these teas can be blended with spices, citrus peels, fresh or dried berries, or herbs you might not be growing yourself such as licorice or sassafras.
Many teas are packed into bags. I prefer to use something called a French coffee press. These come in many sizes and can be made of glass, ceramic, or stainless steel. Probably there are cheap plastic ones or aluminum ones, but you don't want to use these. The way the press works is that you put your loose herb into the container, add water (or other solvent) and then press down with a device that has a strainer type fitting on the end. If you are careful, all the plant material will be under the strainer and what you pour will only be liquid with no more particulates than you would find in a cup of coffee. The glass presses are wonderful for occasional use but the stainless steel ones are obviously hardier and stand up to more wear and tear.
These teas are technically referred to as infusions. They can be made with a single herb or combination of herbs. Besides spices, you can add a small amount of wine, juice, or liqueur. The store has many types of tea but you can easily grow your own herbs and make tea from your own garden.