I've struggled with this same thing two times. I watched and watched my trichs - studying the cloudiness. I read and seen pics, but it didn't make it clear. I harvested way too early once and a little too early the other. The last one, I saw a few amber trichs and thought "it's time". Wrong answer lol.
Idk how many grows you have done, and I'm sure more experienced people will help you more, but I can say (throught the experience that comes from failure) that the best thing to do is watch for problems and glance at trichs until you start seeing amber. Then fight that urge to harvest until you see amber on a large part of buds (not leaves) on the majority of the plant.
Happy growing to ya.