We have a pretty large, awkward wall that just didn't seem to look right no matter what I hung on it. I saw an episode of "Rate My Space" on HGTV where they'd painted this large mural on a massive wall over which they hung lots of different artwork. They explained that the large mural unified the artwork that otherwise might look jumbled together. So I figured maybe I could replicate this on our wall. In the end, we've just ended up with the mural because Michael thinks it will look too busy with anything else on there, and I think I agree.
Anyway, I just Google Image-searched "swirls" which generated quite a few usable swirl patterns from Photoshop (which is well beyond my means). I printed one off that I liked and sketched out a draft using my print-out as an example. From there, I wanted to ensure that I was actually capable of painting something so detailed, so I bought a small canvas, sketched it out, and painted it. It turned out well, and I proceeded by sketching it out on the wall. I really should have gridded it out first, because all the proportions from the small sketch weren't exactly replicated on the wall but not really a big deal in the end. So I painted a different color each night after work:
Day 1: Yellow
Day 2: Blue
Day 3: Green
Day 4: Red
I'm really satisfied with the way it ended up. Clearly, it's not everyone's style, but I think it adds a little something beyond just hanging another picture.