most people say to check your trichromes with 30X magnification. when buds are done they look done. the appearance of the bud changes, the leaves start to hook upwards and start to hard and crispy. the calyxes will swell and the hairs will turn brown. you can see a golden tinge to the bud leaves and this is the amber crystals. they start to turn amber on the leaves first. Red doesn't mean they are done but more then 75% are brown then yeah harvest.