If you want a more pure sativa experience- grow an extra one to make up the difference in yield and chop them a little early- even with photos I don't like anymore than 10% amber... Which means with photos I'm flushing before I ever see any amber.
With autos I start my flush at 50/50 clear /cloudy.
I'm a sativa guy through and through, I don't like the typical indica experience at all- and i gind most sati/indica hybrids pretty boring in the head- if they are even present there-just for a little background about my point of view.