Patience, patience.... is a much required tool at this point. Knowledge of various things have gotten you to this point, try to use the same to determine harvest timing.
My fav scope to gather info is a simple jewelers loop, prob 30x. Know your strain and any tendancies it may have, know the type of buzz you want.....etc, etc.... takes a little practice to see the diff in clear to milky but the amber will definitely show up. Also check those fine hairs to see what they're doing...I like to see mine browning and shrinking back into the bud.....
I personally harvest when trics are milky w/20-30%amber as I prefer some "UP" more than couchlock. It's all up to you but you'll only find your happy medium with patience ....Have fun ........