Draw a tree basis — a trunk, then represent its main branches.
Farther we do a sketch where will be there is a foliage, since an oak old therefore it not everywhere and on a tree is also not live branches.
Now we use a method of curls (a lesson here who is not familiar with this type of shading) we fill a tree with foliage.
We darken branches which new are in a shadow and dorisovyvay. Tree trunk little pritemny.
We take softer pencil and we strengthen a foliage saturation, adding curls in some sites which have to be dark (what dark places have to be, you look at the original, it depends and on lighting), we show a shadow from leaves on an oak trunk.
We add out of need still parts of branches in foliage, at the edges of these deciduous massifs we draw curls still leaves that it looked how a wooliness scraps. Look at the original, you will understand that I mean, I do not know how to explain with words. Dorisovyvayem a grass, the steppe and clouds if you wish and drawing of an oak is ready.
Look still:
1. How to draw a coniferous tree by the same principle
2. A tree for children very simply
3. Tree video pastel