For the anon who asked for scales. The most popular pattern used to make scales in crochet is the crocodile stitch (Youtube tutorial HERE). But you also said that this popular method is too big for the projects that you have in mind, I would suggest maybe using thread and a much smaller hook (like maybe a size 10 or 8) to get smaller scales. Like what is used for lace. Or maybe you could try a shell stitch, which does not pop out like Crocodile stitches do, but are flat with “shells” that kinda look like scales (Youtube tutorial HERE).
Anyways, here are some patterns that use the crocodile stitch: