In my experience, the plants need to "feel" that it's the end of the growing season for them to really ripen. I accomplish this, indoors, by widening the temperature variance between lights on and lights off. I like to go colder at night (~60degreesF) but try to maintain >80degreesF during the day. I also prefer to use the Diminishing Light Schedule -meaning that, at the beginning of flower, I go 12/12. But (typically) a couple weeks later, I reduce it to 13 off and 11 on. A couple weeks after that, I reduce it again, to 14 off and 10 on. A couple weeks after that, I reduce it again, to 15 off and 9 on and then I just keep it there until the plants are ready for harvest -checking the trichomes daily.