Non-Objective

I've been working non-objectively (abstractly) for a few months now. It's hard (has to come entirely out of my head and/or gut) but fun. Generally I do these with mixed media: collage, acrylic paint and inks, drawing, gesso . . . whatever seems to work. It's awfully difficult to know when one is finished, though. I usually paint (or glue or draw) then prop it up for a while until it tells me what to do next, fiddle, prop, etc.
Sometimes they feel finished but I'm never entirely sure. Anyway, here are three paintings in the prop phase waiting for inspiration. Critiques? Suggestions?

River Birch

I think this is finished now, or at least I can't figure out where to go next. I'm not thrilled with the overall shape of the collaged parts but I love the texture! It will take a very deep frame.