One thing I do is pour boiling water from kettle into a pyrex cup. This cools
it almost immediately to 180F. Then when poured into the teapot it's about
170F, which is fine for many green teas. This is for 10 oz. of water in a 10
oz. pot. Your own teaware may vary!

Of course, some greens perform better when cooler and some hotter. I get out
the thermometer when it seems necessary, or when I'm experimenting with a new
tea.

There are many ways to control temp, as you've read in previous posts.

Cheers,
Joe.