I am (was) a jewelry artist and I've been camping with other friends who were either artists or musicians. My vibe is very simply and on the earthier side when I'm in nature. You will look the least creative and/or artistic if all of your clothing looks like they came straight from REI or Patagonia. I think there is a difference between artistic and totally impractical for the situation, so bring your practical outdoor clothes, but also think about how you can bring some visual interest to those clothes. Besides my outdoor basics, I specifically keep clothes in quick-drying fabrics that look nothing like hiking or work out gear for going hiking or camping.
If all your clothes are obvious outdoor-wear, scarves or a cotton print handkercheif over your hair or around your neck and/or jewelry that doesn't get in the way (necklaces, earrings) will add interest to your outfits. If you have some everyday clothes that can double as camp clothes, then you can layer those artistically with a comfortable but stylish sweater, a large wrap, or shawl in a bold color or eye-catching print when it gets cooler at night. I like to pull on comfortable dark jeans or a comfortable dress over leggings around camp in the evening.
Even if someone is dressed very normal at camp, I usually think they are an artist if their camp is put together creatively with pretty and practical use of lighting (battery-operated string lights for seeing around camp), and extra aesthetic touches like a bright tablecloth on the picnic table, wildflowers & greens in an empty tin can or wine bottle, having taken the time to find storage containers and salt/pepper shakers in fun colors or designs, or some obvious sign of creating something from the environment, like rock stacks, pine cone labyrinths, or little collections of interesting pretty shells and leaves.