It seems like it would be easiest to make a one layer card, but actually it's pretty difficult not to put a simple frame, layer, or embellishment on a card. I was playing around with colored pencils a few nights ago for my #100DayProject and ended up with a card that worked for me, so I'm entering it in the AAA Cards Challenge for one layer cards. I'm not using the optional photograph for inspiration.
It had been awhile since I used colored pencils on kraft cardstock, so that's where I started. I stamped Altenew's "Needlework Motif" in black ink on a kraft card base.
The next step was to color the entire image with white pencil so that the colors will appear bright as well as providing some highlights. Given the nature of the stamp, choosing colors was clearly personal preference, and I liked the pinks, oranges, and bright greens together.
The final step was to choose a sentiment. I wanted one that would balance the design on the top a bit since I had decided not to stamp anything from the opposite corner. Papertrey Ink's two-step sentiments from "Scripted" worked well.