My suggestion for pins in-scale is that you should be able to get teeny-tiny straight pins, less than an inch long (I think they're sometimes sold as applique pins or for beading?) and then use needle-nose pliers to bend them in a shape approximating a greek bow fibula (I did an SCA workshop once on making full-size ones out of curtain pins, but the applique pins are the best thing I can think of for doll scale.) (although note that bronze age fibulae could be 6-8" long, so the smallest safety pins you can find probably wouldn't be that far off.)
If you want something fancier, maybe see if you can thrift a handful of small stud earrings? That might be a little more to scale than tie tacks. (We used mismatched earrings as doll brooches when I was a kid.)
I wouldn't worry too much about hemming; I have a human-sized chiton out of cotton broadcloth that I never bothered hemming and despite being worn in tough conditions it's fine. If the doll's not going to be moving a lot, or being machine-washed, you can leave neat straight cuts (like on ancient Greek clothes) unhemmed pretty safely; you might lose a few threads over time but that's it. Or you can brush a narrow strip of watered-down Elmer's glue right on the cuts just to help seal it a little. Or hem by hand! I like hemming by hand. But a lot of doll clothes aren't hemmed anyway, because the increased thickness in the hems doesn't scale down.
If you do want to hem, a very narrow hand-sewn hem would probably look a lot better than a machine-sewn one at doll scale anyway. Or blanket-stitch embroidery around the edges can substitute for a folded hem and look like decorative trim while still being very easy. And if you can embroider a spider-y thing you can hem an 18" square!
no subject
If you want something fancier, maybe see if you can thrift a handful of small stud earrings? That might be a little more to scale than tie tacks. (We used mismatched earrings as doll brooches when I was a kid.)
I wouldn't worry too much about hemming; I have a human-sized chiton out of cotton broadcloth that I never bothered hemming and despite being worn in tough conditions it's fine. If the doll's not going to be moving a lot, or being machine-washed, you can leave neat straight cuts (like on ancient Greek clothes) unhemmed pretty safely; you might lose a few threads over time but that's it. Or you can brush a narrow strip of watered-down Elmer's glue right on the cuts just to help seal it a little. Or hem by hand! I like hemming by hand. But a lot of doll clothes aren't hemmed anyway, because the increased thickness in the hems doesn't scale down.
If you do want to hem, a very narrow hand-sewn hem would probably look a lot better than a machine-sewn one at doll scale anyway. Or blanket-stitch embroidery around the edges can substitute for a folded hem and look like decorative trim while still being very easy. And if you can embroider a spider-y thing you can hem an 18" square!