For my part I expect at least 45/50% amber trichomes, but ideally I prefer to wait for the 65/70%.
It all depends on what you're looking for, if you want to smoke a weed that leaves you active you'll get it at 45/50, but if you want a weed that sticks to the bottom of the couch it's better to wait beyond 65% amber.
The mother strains of your plant will play as well, the indica will be more stoned while the sativa will have higher tones.
✌️😜