This is one of those stitches where the diagram looks kinda "meh." I recommend doing the aqua lines first, followed by the light gray lines, and end with the Smyrna Crosses. Take a look at the stitched sample for a moment to see how wonderful it can be.
I love the concept of stitching the smallest lines (the straight light gray lines) in a different color. In my opinion, it is what makes this stitch stand out. This also provides more thread combination possibilities. The stitched sample uses three threads with two finishes with related color values. To translate the photo to the diagram, the aqua and light gray lines are matte finishes (in related colors) and the darkest gray lines utilize a metallic thread (in a related color).
Another approach is to stitch the light gray lines (both straight and diagonal) in a lightweight metallic with a wonderful single ply silk for the aqua lines. I also love the idea of stitching the three colored lines in three different colors. For example, this could make a great coat for Santa with a matte red thread for the aqua lines, a gold metallic for the straight light gray lines, a red metallic for the diagonal gray lines, and a purple metallic for the Smyrna Cross.
You could do the whole things in a single hue...let's say a blue sky. Stitch the aqua lines in a pearl cotton. Stitch the vertical light gray lines in Flair and the diagonal light gray lines in a lightweight Kreinik Metallic (Fine Braid #8 on 13-mesh and Very Fine Braid #4 on 18-mesh). Stitch the Smyrna Crosses in the same Flair or the same Kreinik Metallic.
This stitch diagram, along with all other #whimsicalwednesday and #smallspacesunday stitch diagrams, can also be found on a Pinterest board here.
If you like what you see on this blog, want to learn some very creative decorative stitches, and how to put them all together, whimsicalstitch.com sells stitch guides for Melissa Shirley Designs and Zecca Designs. 28 guides are currently available, including the newest Tea by the Sea, and more are in the pipeline.
I hope you have the perfect spot for this stitch! Enjoy!