I know this is a couple days old, but I will add anyway!
It's cute ... and I really like it, ScissorQ ... will be interested to follow it as it develops.
Sounds as though this is going to be like a centre medallion, so now And you have me curious as to what the outside will be.
I'd never heard of the rule of thirds ... makes total sense!
Then there's the the rule of three, that you've used for the leaves.
To me, the three leaves are in too much of vertical alignment.
I'd play with moving the branches a little,to switch that up ... or perhaps try moving a leaf over to the thin branch towards the top left. Though that may look too triangular.
Or even break the rule of odds, and add a fourth leaf ... I think five might start to look too many.
You mentioned it's hard to see the balance when you are close up. What I do is take a photo and look at the small version on my camera. Or upload it and shrink it down. Here on the Board, I used the zoom out feature to squish it in for a good look.
It's going to be a fun project to work on ... and I can't wait to see the snow additions!