The slippery yarns (silk, bamboo, modal etc) require a little extra planning and attention to give them supportive structure.

* Cast on tightly with the cable cast on. For added structure to your neckline, consider picking up and knitting the ribbing later (you would cast on the number of stitches needed to begin after the ribbing, and then work the ribbing after the sweater is finished).

* Go down an extra needle size for the ribbing.

* Crochet the neckline! Read the article How to Fix a Sweater that Slides Off for this technique.