Apparently, the common way to use it is to put in a lot of leaves at the start of the day and just keep filling it with hot water throughout the day as it gets bitter. By the end of the day you're just drinking hot water. I've never really got on well with doing that, so I prefer to use a smaller amount of leaf and drink it dry before the bitterness sets in.
I only recently discovered the "official" concept of distinguishing between putting the tea in first then pouring water on top (xia tou), or putting in a small amount of water followed by tea then more water (zhong tou), or putting the leaves on top of the water (shang tou).
For this glass, I've always put the leaves on top and watched them float down (and smelled them!) and felt vaguely guilty that I wasn't doing it the "proper" way. I just do it because I like watching the leaves sink, and I absolutely love the smell.
As an aside, I've only seen this brewing distinction mentioned in a few places. In one place, it was translated as "top throw". From that, I imagine that the Chinese is "投" ("tóu": shàngtóu - 上投 - top throw, zhōngtóu - 中投 - middle throw, xiàtóu - 下投 - bottom throw). Can anyone correct me on that?
Regardless, I can highly recommend these glasses as a way to enjoy (Chinese) green tea, and I can also highly recommend Xiu Xian Tea, who were incredibly helpful with getting it shipped to Germany, and sending me replacement filters when I accidentally flushed mine away!
