When to harvest Marijuana buds?

Great video. I'm just finishing up my first grow and have been trying to decide if they're done or not. I see the odd amber trich but mostly cloudy with about 10-15% clear. I've been feeding just water for a week or so...I think it's time to cut three of my plants down. The other three keeps growing new pistols and no amber trichs yet so I'm going to leave them for another few days I think