I used this helpful post as well as their website to guide me, and found that as long as you just trust that you are walking in the right direction, you'll get there eventually.
I experimented with various combinations, including a color-changing one-ply yarn in various shades of brown along with a strand of what sort of looked like sprinkles to perhaps make a chocolate cupcake cowl. But in the end, doing something like that had the downside of doubling the cost, so instead I chose to just take 40 g of a heavy fingering (maybe DK) yarn that reminded me of Noro in the coloring, along with a little grab bag that had a short amount of a pre-made art yarn concoction that seemed to complement it.
In one of the crafting department stores (I hope to outline a few in a later post) I found a plain black in the same gauge also from a Japanese yarn company, called Puppy. So these will likely be combined to create a shawlette, with the tiny yardage of art yarn going towards a knitted flower or other embellishment, possibly to act as a closure for the shawl.
I highly recommend a trip to Kichijoji and this store. It was a really interesting experience to find something that felt very much like a local yarn store in the US, with people knitting in the side room, etc. The other yarn sources I was able to make it to were all more like department stores, so this was absolutely worth the journey out, especially because Kichijoji itself turned out to be such a gem of a little town for wandering and shopping.
You know, when you next happen to be wandering around Tokyo wondering what to do with yourself.