Here's my best tip.
I've got one grow under my belt. I harvested 3 out of 4 plants when I thought they were done. Then, I decided to let the other one keep going. THEN, I ended up having to go out of town and there was an extra 3-4 days or so added on to the week extra I already decided.
There was a NOTICEABLE difference in bud swell, the hairs had receded nearly ALL THE WAY back into the bud, and it was just plain different to the naked eye.
I harvested, dried, and cured that bud.
First 3 out of 4 were 5-6 out of 10 in terms of high.
The plant that I let go...8-9.
YOU WILL KNOW.
GL!
edit: And also, Pic 1, I don't see a single amber. I know people say "amber is degraded THC, you don't want that."
True. BUT, it is also an excellent indicator. I see zero amber there. IMHO, 10-20% amber is desirable to get the max effect out of the other 80-90%.