Well, I know it doesn't look like much, but it's a start. I'd been wondering how to continue the ditch (still hard to call it a creek at this point) under the fencing, without giving our dog a clear exit point. The nice discovery was that (duh) the fencing goes down into the ground about 6 in.; and with some strategically-placed rocks in the same spot, we should still have a dog in our backyard.
I started out drawing a design of the curvature I wanted for the creek, but gave up and just dug. I like how it turned out and can still adjust if I want.
Since this last photo, I've doubled the width of this section of creek. We're debating how wide to make it in the end.
Creating it slowly does have its advantages, esp during our "rainy season." I'm able to see the grading and how the water flows after each rain, and can make adjustments. The downside is, the rain ends up washing back in some of the dirt I'd previously excavated. Not much, but it does feel like two steps forward, one step back. Onward!