If you are making an herbal tea from a pre-made (often in bag form) supply. Check it side of the container for specific instructions.
GENERAL INSTRUCTIONS: place two teaspoons (or one bag) of herbal mixture into a teapot, pour BOILING water over it, cover and allow to steep 5-15 minutes. If using loose leaf, strain the tea, sweeten to taste. It has been my experience that most herbal teas are not good with milk added, but if you feel the need, go ahead and try.
If you are making herbal tea from raw materials (various herbs, root, barks, flowers, and leaves according to the recipe you have worked out for your personal need), measure the various ingredients and place into a large (airtight) container, mix thoroughly, cover, label carefully with ingredients & date and set aside. When you want to make some of your tea follow the above general instructions.