Get a magnifing glass and look a the trichromes ( frosty looking stuff on the leaves and buds) when the plant is in the early stages of flowering they are all clear, at mid point they will begin to turn cloudy, when at the end of flower are amber.

If you harvest when the trich's are clear you get an enerjetic body high ( note: much smaller final yeild than the other 2 periods ), 50/50 clear/cloudy you get a more cerebal energetic buzz, 50/50 cloudy/ amber is a couchlock buzz. Harvesting during any of these 2 periods will not have much of an affect on your final yeild.

I harvest at the first sign of Amber, getting the cerebal with some couchlock. I think you can get how it works now good luck.

JG