Instructions for the tree that Mr.LoL posted a pic of.
Plant randomly that kind of roudbricks you see in the picture for about 1-2 bricks high "puck".
(Don't make anything symmetric, just randomly)
Then dupe that "puck" and rotate it, plant the dup about 1-2 bricks higher, rotate again and continue with this until your roudbrickpile is high enough. Then jump on it and put it in a shape with D-wand, if you manage to give it a tree-like shape, then you can finish the shape and move on to the top
(the top is usually flat right now) Then plant few bricks like in the picture to make the top tree-like.
Bew, if you are lucky and nothing went wrong, you have a tree.
-Edit-
These really are the real and original instructions for that tree MrLoL posted a pic of, atleast that is how that tree in the picture was made. I know it becuase the TREE itself was made by me.