My yarn ends keep working their way out. How do I secure them properly?

A knot in a single strand of yarn holds by friction between two loops of the same fibre. Every wash, every stretch and every load cycled through a stuffed toy works those loops looser. Over a year a square knot in DK acrylic can work itself down to a slip knot and then to nothing.

A knot also fails loudly: when it goes, a whole seam opens rather than one stitch loosening. That is the real argument against it — not that it looks bad, but that its failure mode is catastrophic rather than gradual.

Thread the tail on a blunt tapestry needle. Pass it under three stitch posts, always going under a whole post rather than through the middle of the yarn — splitting the strand weakens it and shows on the surface. Pull snug but not tight enough to distort the stitches.

Change direction by 90 degrees and pass under three more posts, then change direction once more and do three more. Three passes in three directions gives you friction in three axes, which is what actually holds. Trim the tail flush with the fabric, not longer — a 2 mm stub is more visible than a flush end.

In amigurumi under 5 cm there is often not enough fabric to weave in three directions without it showing through. Work the tail into the stuffing instead: thread it, pass the needle up through the inside of the piece, out through the fabric two stitches from where you started, and pull until the tail disappears inside.

Alternative that works well for tiny pieces: split the tail into its two plies, weave each ply separately in opposite directions, then tie them together loosely with a single overhand knot that sits inside the stuffing. The knot is now inside a stuffed cavity, so nothing pulls on it.