I've put about 20-25 hours of fairly strenuous labor into this triceratops head. I wasn't sure where I was on the love/hate continuum with it yesterday: something about it just bugged me and I couldn't let it go. I figured out what I wanted to do overnight and was fortunate to be able to put in another hour today making it happen. It's still not what I see in my head, but I'm more securely on the "love" side of the see-saw now, so I'm going to call it good and move on.
This triceratops head is obviously far more elaborate than the first one I constructed. I've taught myself some tricks as I've built things over the years (in fits and starts), and I've become more confident in my ability to create shapes from scratch. But this still isn't the triceratops head I want to make: it's closer, but it's not there yet.