Hey man! Ladies are looking good
Flushing is a controversial subject
It's each to their own. Personally I flush. I envy those who don't need to.
Both myself and Bill use the trichomes as a guide when to harvest. This is quite a common practise.
Seeing as I flush, I aim to flush a week or so before I want to harvest.
For a sativa, this would be when the majority of the trichomes are cloudy.
For an indica, I might wait for some more amber to appear before flushing for a more couch lock high.
Whether you decide to flush or not, I'd recommend going by the trichomes. If you don't flush its simpler, you just chop when you are happy with the trichomes. If you do flush, you need to start a little before your trichomes are where you want them to be