Well done Mark, that is what it is completely about, ' seeing within'.
You see Mark you nailed it, forget the air layer...your top drawing was considered, but I found two of the branches a little bit thick (not much in it but a little to throw me) to start with if I cut back to your spot, but to be fair i have the luxury of the tree in front of me, if I went that way probably stagger the heights.
The other idea is getting close to where I m at, with the bones you have taken and left, you see you do have vision and some of us just need pushing and a little coaxing to get it out...well done.
You see my post is not about how good you can or cannot draw, vision can come from many forms..imagination, looking at individual trees in forests, your mates trees, forum trees and so on, I feel every body has it and really nothing to do with experience, you just have to know how to express it in some way so you can apply it to your trees, basic line drawings and photos just to name two.
Just putting horticulture a side, physiology then comes next...how it functions, works, meaning can I apply its growing traits to my ideas etc, thats where experience can greatly help to I feel.
But back to design...once again well done Mark, nothing wrong with your sketches, why, because I can understand them.
Sorry you will have wait little bit longer for my design buddy lol
cheers Anthony