To add a new skein join new yarn at the end of a row whenever possible. To do this, work the last stitch with the old yarn until two loops remain on the hook, then with the new yarn complete the stitch.
To join new yarn in the middle of a row, when about 12 inches of the old yarn remains, work several more stitches with the old yarn, working the stitches over the end of new yarn (shown in double crochet). Then change yarns in stitch as previously explained.
Continuing with the new yarn, work the following stitches over the old yarn end.