We tried a very haphazard version of mint tea using lemon mint a few days ago. This time I used peppermint and actually dried it before brewing.
I took the peppermint leaves and dried them in my dehydrator. You could air dry them too, it would just take longer and I already had the dehydrator running. If you do air dry them you can hang them upside down in a paper bag. Make sure they have enough room around them for air to circulate and leave them for a few days. The time they take to dry will depend on your weather. The paper bag is to keep dust off of them.
After I dried the leaves I ground them in my mortar and pestle and put about a tablespoon of the ground up leaves in a reusable tea ball. Then I put that in a pitcher of hot water and let it brew for a few minutes. Then I put the pitcher in the fridge and had some cold later. It was really good. I was afraid it would not be minty enough and the hero was afraid it would be too minty, but it was perfect. A very refreshing and healthy drink! I suspect it would be good hot too.