Not much time but here are some suggestions, interpretation, as I might think something looks good but others might not
The red dots are where i've added stuff, the blue lines, these areas are too heavy makes the leaf slab-like, also the shading should take the form of the leaf as below.
The green shading is straight and at a different angle than the design, it should flow in the same curve as the leaf above.
I forgot to mention, the black areas should all be roughly the same size, ie. the one at the centre of the large scroll and the one on the left are bigger, room for a small leaf in each.