How to pick up a dropped stitch while in garter stitch with out using a crochet hook
Fixing a dropped edge stitch.
Mending your knitting
Diagnose and remedy holes in knitting

Correcting mistakes in lace knitting
It is pure genius, makes so much sense. It’s long but very much worth the time to watch. I think the concept could brilliantly be applied to fixing a mistake in any pattern. A “why didn’t I think of that” moment.
Fixing a dropped German short row Stitch
I’ve now tried this, but looks interesting.