Before adding the leaves the tree needed some finer branches. So I sprinkled on some static grass fibres. First 6 mm fibres and then 3 mm fibres. I used ordinary hairspray to make the fibres stick. The picture below shows the tree after this step. The stem is covered with a piece of paper to avoid any hairspray or fibres to end up on it.
The next and last step was to add the leaves. I used Noch Leaves, Light Green (#07142). Once again, hairspray was used to "glue" the leaves to the tree. Here is the final result.