Good news! I've been enlightened!
There's a very clear divide between certain bits of artwork, and i thought it might be interesting for me to touch on why that is:
I'm really lucky in the sense that I'm designing -and- modelling a lot of these concepts. This is really great, because if I'm strapped for time or already have a really clear picture in my head about what I want an asset to look like, I can sketch out the roughest of rough thumbnails, and that's enough for me to get started and give the rest of the team a vague idea of what I'm imagining. It's such a glorious time saver. Don't get me wrong, I also really like making high-polish production art, but I tend to save that extra time and effort for assets that really demand a lot of planning and design work before hand. I think that contrast between my different workflows will be abundantly clear later on as I post some more recent artwork. You can see a less dramatic example if you compare this smith guy's art (which is still pretty rough) with Cenn from my last post.