White Pain au Levain pics and some questions about ears

I've been quite bad at uploading pictures of every bake and routinely miss a number of them, but here a couple late pictures of the most recent bake! 100% White Pain au Levain. Nice and creamy and tangy just the way I like it - 12 hour bulk ferment and a 12 hour refrigerated proof. My Girlfriend decided to score my initial into the top which came out in bubble letter form and I quite like it, may have to work on perfecting that XD 

Anyway, this bake got me wondering: I usually get very good grigne and some small ears, but I'm wondering if I'm missing something for better ears in general? Usually I'll proof till the finger-dent test tells me it's ready to go, then bake in a cast iron pan with an identical cast iron pan flipped upside down on top of it (an impromptu dutch oven). The pans and oven are preheated to 475f. With many loaves I just bake them seam-side up and let the natural seams from shaping split and be random and beautiful. Sometimes I'll bake it with the rounded side up and score it (as I did with this loaf). I suspect it's something to do with the scoring, but any other pointers you have are greatly appreciated. 

Anywho, without further ado, here are the pics: