Just like any strain I look at the trichomes with a pocket microscope. You are looking at the little ball on top to see if it has turned milky (ripe) or amber (over ripe). The trichomes will not all be the same so you are looking for an average. The fewer amber the more "high" it will be but if you want a more relaxing "stoned" then wait for more to turn amber.
Hi buddy
not ready yet... i would wait 2-3 more weeks before flushing!!
Anyway here's photo to better understand:
https://www.royalqueenseeds.it/blog-l-importanza-dei-tricomi-nella-cannabis-n430
good luck with your grow mate!!!💪🙏