I just made three more pairs of tights, using the pattern I made by tracing a commercially-made pair of sewn tights.
The peach and pale pink pairs are made from rib knit, and are slightly baggy, but will be fine for a layer of warmth and worn with additional socks and boots of various styles.
The gray... Using the exact same pattern as the rib knit versions, the gray ended up being too short. I have suspicions how that happened (knit fabrics are variable beyond my comprehension), but I'll mostly say it was disappointing, because the fit around the legs was perfect.
After some thought, I picked apart the center seams and sewed extensions on where the crotch should have been, then re-cut the top of the tights. I also added more height to the top, because it's vital for my comfort that tights go all the way over my bulgy abdomen. I had to piece that extended height, too, which was an actual benefit, because it allowed me to use up almost all of this fabric (left over from a previous project that left me unenthused.) So, these tights have a whole bunch of weird seams, but they're up where no-one will ever see, and they didn't seem obtrusive when I tried them on, so it's fine.
Everything is stitched with a narrow zigzag, and finished with serging for extra security. I still don't trust my serger to sew with two needles without breaking the left needle, but I don't have problems sewing knits on the lockstitch machine (as long as I use good thread.)
So! Tights! Sewn tights!