Generally it is recommended that you use once teaspoon of leaves per 350ml cup of tea. However, some lighter teas require twice that. To steep red, dark oolong and puerh teas use 90C water. When steeping green, and light oolong teas it's important to use cooler (80C) water. Remember not to over-steep or your tea will taste bitter, around 1.5 minutes is good. If you would like to have stronger tea then add more leaves rather than brew for longer.