Next came the image processing. This has been something of a steep learning curve, but thanks to Ian's Digital Techniques group notes and several YouTube tutorials, I am getting the hang of it.
First off, I went for some simple mono conversions.
Next, for a couple of the images that had no sky, I played with the hue and saturations in Lightroom alone.
Finally, I dived into 'channel swapping', using Photoshop to change reds to blues, and blues to reds. These would have been stronger with a better sky, but I am happy with them for a first go.