It's depends on thw type of high you are looking for, if you harvest with 50/50 milky trichomes you'll have a more energetic and rushy high, if you wait till full cloudy very lil amber you will have more of a hybrid high and if you wait full cloudy with a lot more amber you'll have a Narcotics or sedative high. 2 days before you decide to harvest leave the lights on for 48hrs to increase trichomes, others will say no you need 48hrs of darkness but Dr Bruce Bugsbee, A professor from Cornell, debunked that myth and plenty more other bro myths. Look him up and you learn a lot from him. Good luck and happy growing