I look for small stems snapping. Like the tiny ones that hold on leaves or small side buds. When they snap or are close to I’ll final trim then start slow sweating out the rest by sealing and breathing them over a few days.
Usually at that stage I trim and put the nugs into a foil baking pan (closed with lid) for a dayish then open it for a couple hours, repeat until satisfied. The ‘roll a J’ test never lies too. You’d be surprised how wet they can feel but roll and burn great. I store longer term so I go past that point to avoid mould etc but that seems to be the sweet spot.