I'm happy I managed to continue the shape of one of the triangles in the binding:
And I added a tiny triangle in the binding on the left side:
I thought about adding another layer of machine quilting in another colour or maybe adding shapes of triangles hand quilted with thicker thread... but I really don't know. I don't want to 'overdo' it.
The hanging sleeve isn't attached yet...
Thanks for your suggestions !
Heidi