Canon EOS 3,
One afternoon in the Blue Ridge Mountains of North Carolina, at a scenic overlook, the wildflowers on the other side of the road beckoned to me from their location down in a gully a bit, so naturally I went ambling through the underbrush to get the framing. While the sky was a bit more busy than I liked, it works pretty well in monochrome, perhaps even better than the color version.
While you can always just convert to greyscale in an editing program, there are other options. A simple one is to examine each of the three color channels (assuming you're working in RGB mode) and see which one seems to produce the best results from contrast and detail, then delete the other two. Then you can convert to greyscale, and see what it produces. This one is strictly the red channel, which deepened the appearance of the foliage which was, surprisingly, lacking in red. Afterwards I tweaked the curves a bit to bring out the layers of peaks and the details of the sky more distinctly. It helps make up for not being able to find a blossom in the right position to get close to and dominate the foreground with.