UV tiling and layering feels old-school clever, almost 8-bit clever. Such a simple thing to do, but it takes wrapping my head around unwraps first (oh dear, that sounds recursive).
I’ve not applied this concept much before, even though I’ve always admired it. I don’t usually do so much 3D art, but now that I’ve dug myself in, I’m enjoying it immensely.
Here’s my example of a small texture (highpoly baked) that repeats many times across my scene. A rubber mat. I’m saving a ton of texture space here, even though I’m not nearly as meticulous as some of the examples I’ve seen elsewhere. The corners and ramps were the only tricky bits.