Trees

I have decided to work on some of the gaps in my artistic skills. I can sometimes draw buildings well enough to garner praise from friends and family; I cannot reliably draw a tree so well that it actually looks like a tree. So a-googling I did go, and found this on youtube:

My first attempt at using the technique:

tree1

and some tree-containing sketches of things visible through the windows:

tree2

trees3

trees4.

Respond.