The hairs, (pistils) will give you an idea but its better to go with what the trichomes are saying. Grab a cheap jeweler's loop, even 10x magnification will help, (I use 60x) when the trichomes have formed the bulbous tips and appear to be milky white in color is the time to harvest. If the tips of the trichomes start popping and the trichomes begin to turn amber, that means you're over the mark.
If the trichomes look ready but the pistils are still white, (you should have been flushing for two weeks at this point if you're not growing hydro) a cold water flush will help speed up bud maturity. You may also try an extended dark period before harvest 24 - 48 hours. This will also force the buds to mature faster.
Yes usually the last 7 to 10 days it's only water but I don't flush per say, I give the plant what I feel it needs, I would never withhold nutrients for x amount of weeks as in a basic flush
This is a Hot Topic though I used to flush in Hydro but I don't in soil, but everybody's got their own opinion on flushing & that's mine, good luck
Thanks for all the input guys!! The support on all this is great, me and my old man are growing together and we’re trying different lights to see the results. The pic you see here is one I got from a friend pretty early on in it’s life so I’m decently proud lol especially for me first grow