Every time you finish a ball of yarn and join a new one or change colors in the middle of a stripe pattern, you’ll find yourself with loose ends. In order to tuck in these stragglers and create a truly finished-looking product, you must weave them into the wrong side of the knitted fabric.
To do this, carefully untie the knot you made when joining new yarn. Thread one of the loose strands through a yarn needle and snake the needle (and attached yarn) down through approximately five of the free loops along the edge of your knitting. Snip close to the work to remove whatever’s left, being very careful not to cut into the actual knitting. To secure the second strand, thread it through the yarn needle and weave up.
If you have to change yarns in the middle of a row, untie the knot and weave one loose piece in each horizontal direction, following the path of the affected stitch through five or six additional stitches on the wrong side of the work. Always double check the right side of the fabric to make sure there is no puckering or unsightly looseness where the ends began.