Are you repairing a knitted garment? Place the unravelling part over the bristles of a brush - they will hold the knit and prevent it from stretching.
To repair holes in a sweater, place a piece of muslin or net on the wrong side of it, then dam right through its holes.
For a quick repair when your sweater snags, pull the loose loops to the inside and secure them with a hair pin or paper clip until you can get home and restitch them.
