A beloved skirt (not so recently) developed a hole. The fabric is so thin, and such an odd color I didn't dare patch it... so it sat on the sewing table for months (except the times I popped duct tape on the inside and brazenly wore it out anyway...)
the evil hole.
Anyhow, the other day I decided to try darning. For anyone unfamiliar, darning is basically reweaving a small section of cloth - usually mentioned with socks, but it works for anything. I just stitched back and forth a few times vertically (going about a centimeter beyond the hole) and then across horizontally, weaving the threads in place. (Hand sewing, although I understand with sturdier fabrics, it can be done by machine, sewing, rather than weaving, the threads together.)
its effectively invisible when worn
The whole process took maybe 10 minutes, and a beloved skirt is saved! Also, the repair is all but invisible, so I'm feeling pretty smug.