poster development

I have been focusing a lot on the style to draw my poster, and have been continuously drawing alice sat on the dodos knee, but haven't actually thought about the composition of the poster.
I tried seeing how the sketch I've been working from looks on a page, and it seems rather empty, just floating on the page with nothing surrounding it.
So I've started thinking about how to compose it

Like idea of having elements of the Alice in Wonderland stories come into the poster, as so far it isn't too clear who the person I'm depicting is, as he is most famous for his Alice books. 
It would also give the sense of him actually in the process of telling a story to Alice, which is something he apparently enjoyed doing. 

I feel the style of the pen work and the loose watercolour makes the scene quite dreamlike, which relates to Alice in Wonderland as much of it is very surreal.