Hi. I don't recall what was discussed in that thread/those threads, but you should tackle a couple that seem the most intuitive to you and see how it goes. There is hot glue to think about (dab and "plant"), Making a small plug, about a couple of teaspoons worth, of plaster, or hydrocal, or sculptamold, ground goop, and put a dollop around a tree that is already partially inserted into a drilled hole of suitable size should work. You can drill the hole, and also one in a small piece of plywood or 1X2, and tape that to the nether end of the first hole. Sink the armature into the plywood block for the stability you want. Lots of work, mind you, for a single tree.
Personally, where I want poles and trees is where I add a second or even a third layer of the goop. That may mean enough weight that the added layers should be spread around a sufficiently large area to ensure strength to prevent cracking and collapse.
Today I tried drilling a 1/6" hole through the plaster/hydrocal shell and just inserted the wire trunk in it. It seemed to work okay but the tree was very loose. I'm not exactly at the planting stage yet but I'm thinking this would be a good way to start and then use the hot glue on the trunk and surrounding area. I am thinking that the cat is going to have a heck of a time some day when I'm at work though! Ha. Thanks for the directions...........