Right after harvest, while the leaves are still wet. I've always trimmed right away. Helps it dry evenly.
Trim it all as soon as you take it down, if you're working on your own and have a few plants to get through, do them one at a time and if they are big plants cut down parts at a time and trim them before taking down the rest. If you chop all the branches down and it takes you 12 or so hours or longer to trim, some of the leaves and stems will start to wilt making it harder or just more awkward to trim so leave them on the plant and work through it gradually.
your cutters get less gummed up if you let it dry a bit before trimming makes life alot easier imo especially if you can't get in one sitting
I do mine right away. I know people do it when the leaves are dry, but I find that it makes the buds have a bit of a "hay" like taste to them.
I've found the exact opposite. I've tried hang drying plants for a few days or week and then trimming them. The leaves lay down next to the plant and are harder to trim off. It really seems to be more messy to me and stickier. It gummed everything up quicker and you have to fish each leaf trim out with the tip of the scissors. IMO plants are best trimmed fresh just like salad. The leaves are standing right out waiting to be trimmed off. The stems break crisply when the plant is freshly cut. Once they wilt they become tougher to remove. If you don't have help to the point that you can completely trim a whole plant in a sitting of a few hours then do partial harvesting. That's what I've been doing. It will actually take me a week or more a couple of hours a night to trim my bud tent out. I've started to dread it... lol. It's the worst part of growing. I'll select a branch I want to trim and remove it from the plant with some heavy clippers near the main stem. The rest of the plant stays. I sit back with my trim tray. I first remove all fan leaves by hand and disguard them. I then remove all airy smaller larf buds near the bottom and they go in an edibles paper bag. Once I'm down to the actual buds I'll spin the branch with one hand and trim the sugar leafs and tips off with the other. Those also go in the edibles paper bag with the larf buds. The trimmed down large branch goes on a drying rack so they aren't touching each other and I move on to the next one. I'll remove the buds from the branch after about 5 days on the rack when it's ready for a jar. If I get to 3 or 4 branches that night then the rest of the plant lives another night. I just keep removing branches and trimming them one at a time starting with the most ripe plant in the bud tent until it's cleared out. Like I said it can take a week to 10 days depending on how motivated I am to trim, my amount of spare time, and how much help I can find.
Some people will reach in the tent and remove every fan leaf from the plant by hand when the buds are ready for harvest in one fail swoop a day or two before chopping it down as part of the flush process. This will remove a large portion of leftover chlorophyll from the plant that can influence that hay like flavor in the buds. I haven't tried it but I have heard of other growers who employ this practice. It seems to help with the cure process.