There is no need to trim the popcorn. It just has some little leaves attached to it, and those little leaves have trichomes on them. If it has resin on it, you can pull it off with an extraction method - bubble hash, butter, BHO... There is a lot of personal preference when it comes to trimming and drying. Here's how I do it. I cut a branch off right at the main stem and pull off any fan leaves (leaves with a stem.) Then I have something like this:
Once the branches are all stripped of fan leaves, I wash with the three step system and shake off excess moisture and let the branches dry on some paper toweling for a bit. I dry on a screen, so I break things down next. Little buds that aren't worth drying for smoke are tossed right into the trim bowl. I don't trim sugar leaves off them since they are for extraction anyway. Pretty much all of the leaves from the first picture and all the little popcorn nugs are in the bowl. They go right into the freezer.
Last, I separate nugs - breaking down things as far as logically possible and end up with this:
I dry the nugs on a screen. It's quite dry where I live and they dry fast. You don't want them to dry too fast because you want the chlorophyll to degrade. Because of the dry climate I put the nugs into jars before they are dry for a couple of hours a couple of times so they even-out moisture wise. When the stems snap easily, I put them in jars for the last time with a boveda 62% pack to cure.
Hope you don't mind the pictures, VG. As an alternative, you can hang larger hunks of stem with nugs attached to dry and do a final trim of the sugar leaves after drying and then break down the colas into individual nugs before putting them into the jar.
There's lots of ways to go about it...