- or darning while knitting.
You can fasten off yarns by weaving in the tails while knitting on the right side. The woven-in yarns lie on the worng side and are not visible on the right side. Hold the work as for knitting Fair Isle knitting. Se my Danish video here!
If you are as lazy as I am - weave in as many tails as possible this way.
When using this technique it is no problem to use many colors.
It is difficult to weave in tails when knitting on the wrong side, so don't try.
In some patterns I refer to weaving in yarn tails “wyt-col A”, meaning: weave in the color A yarn tail. If there is no such reference, weave in tails when you find it adequate. Always weave in the tail that is the lowest. Then weave in the tail that is now the lowest etc.
After weaving in a yarn tail, knit a few more rows, and leave a 1 cm /1/3” long tail on the wrong side to prevent it from slipping on to the right side when the garment is laundered.