Add the matcha to a spouted bowl or a glass liquid measuring cup. Add a drizzle of the cool water and whisk to form the matcha into a paste. Add remaining cool water and whisk vigorously back and forth until thick foamy layer appears, about 20 to 30 seconds. (For the best froth, avoid whisking in circular pattern.) Alternately, shake matcha powder and cool water in a jar until frothy.
Stir the hot water and honey in a mug. Pour the foamy matcha into the mug, then stir gently and adjust the sweetness to taste.