I like that. Good rule to go by. I'm trying find that way myself and asking people to see what's similar what's not and what's best for me . I have two seasons I have to make sure I don't harvest.. three months window. In summer but rained so much this year. I have to have a planned out timing grow just about. Had two got mold. But I think I'll solve that with not buying big huge nug plants. I can't mature them before mold. It control it without spending thousands.. and cure process I'm just lost.. got make the plant down pat. But rest. Still learningSo my friend.
Getting it at just the right time is a little subjective to each person. Or more so as to what kind of high you're wanting to target.
The usual rule for me is don't go by sugar leaf trichs go by flower only. Always make sure you've gotten a good fade to the plant also. So a good flush to help knock chlorophyll out.
I use a usb digital scope so can get the best view to judge trichome maturity. My ratio is 60-70% amber. 20-30% Milky and norm 5-10% are clear to milky. This way you get a balanced high that's nicely rounded. Yet if you want to stimulate say appetite then I'd harvest earlier.
Then nice slow drying normally takes me 2 weeks from chop to trim.