Hi mate, it depends what type of affect your after, the plant is actually ready when its 100% cloudy, this is just before the thc starts to degrade and this is what the amber trichs are, its turning the thc into more cbd, this is basically the couch lock affect, so the more amber you have the more couch lock affect you will get, but the plant is 100% ready when all trichs are cloudy so check the leaves on several bud sites and make sure their all cloudy, and as you have said you have some amber trichs then you can harvest when your ready mate, i just harvested the top half of my nl x bb and this was 100% cloudy and on each sweet leaf it had 3 or 4 amber trichs at each bud site and on each leaf so i harvested that 2 days ago, i have left the bottom half of the plant to go further as it was not getting the light so i had lots of small buds, i am leaving these on and its back under the lights, i have also got another nl x bb which was taken from the same mother as the one i harvested and im going to let this go a lot further, ill leave it till its about 30% amber trichs, that way i can compare the difference and decide when i want to harvest next time.
if you have not all ready done this then take off a couple of small bud and quick dry it, then test it and see if its the affect you want, it wont taste as nice as slow dried buds but it will be the same affect and type of high, so you could try that and quick dry it and test it and if thats what your looking for then harvest away my frined