First things first, if you are going to make an herbal infusion (aka herbal tea) and you are expecting to receive benefit of it's herbal properties, PLEASE USE DISTILLED WATER!
If you do not, you may not be absorbing all the important properties of the herbs into your water as you could be if the water was distilled. Since distilled water is pure water having all other matter (organic and inorganic) removed from the distillation process, the water therefore has the ability to more readily absorb the herbal constituents of the infusion.
This is such an important part of making a true herbal infusion, but it is the most overlooked step. Herbs are God's gift to us and getting the most benefit from them is only to our help.
Next, when making a tea, if the herb is loose, a good estimate is approximately 1 teaspoon of herb to 1 cup of hot water. Lastly, steep for about 15 minutes and then you are ready to enjoy your tea and all of its benefits for you.