I am knitting a gauge swatch in stockinette stitch right now with a garter stitch border to prevent curling and hopefully get a more accurate gauge. I have already measured myself for making the skirt.
Now once I get the gauge, I am thinking of multiplying that stitches per inch by a measurement a bit smaller than what I measured myself to be so that I know how many stitches to use for the ribbing. I haven't decided on yarn yet but I want to use a soft acrylic that is worsted weight. I have decided on using size US 8 circular needles. As long as I use the same yarn weight and needle size, gauge doesn't change from brand to brand.
I have restricted myself to using 4x4 ribbing or smaller. So the number of stitches I calculate will restrict that further based on factorization. Anyway, since I have a lot of yarn that I wouldn't use for other projects(mostly variegated is what I wouldn't use) should I knit about an inch of every ribbing that factorization will allow in the round as separate waistbands, bind off, and try them on?
And how will I know when I have found a good ribbing to be both elastic enough to stretch when I change position and sturdy enough to hold the whole skirt up when I don't know yet how much the rest of the skirt will weigh compared to the ribbing?