I think this should work for a symmetrical scarf with 3 cables and lace between them.
Cast on 46 stitches.
Row 1 (RS): K7, p3, k2tog, yo, p2, k2tog, yo, p4, K6, p3, k2tog, yo, p2, k2tog, yo, p4, K7
Row 2 and all even rows:
Work stitches as they show up: Purls are purled,
knit stitches are knit. Yarn-overs are purled.
Row 3: k7, p2, k2tog, yo, p2, k2tog, yo, p5, k6, p2, k2tog, yo, p2, k2tog, yo, p5, k7
Row 5: k1, C6F, p5, k2tog, yo, p6, C6F, p5, k2tog, yo, p6, C6F, k1
Row 7: k7, p4, k2tog, yo, p2, k2tog, yo, p3, k6, p4, k2tog, yo, p2, k2tog, yo, p3, k7
Row 9: k7, p3, k2tog, yo, p2, k2tog, yo, p4, k6, p3, k2tog, yo, p2, k2tog, yo, p4, k7
Row 11: k7, p2, k2tog, yo, p2, k2tog, yo, p5, k6, p2, k2tog, yo, p2, k2tog, yo, p5, k7
Row 13: k1, C6F, p4, yo, skp, p2, yo, skp, p3, C6F, p4, yo, skp, p2, yo, skp, p3, C6F, k1
Row 15: k7, p5, yo, skp, p2, yo, skp, p2, k6, p5, yo, skp, p2, yo, skp, p2, k7
Row 17: k7, p6, yo, skp, p5, k6, p6, yo, skp, p5, k7
Row 19: k7, p3, yo, skp, p2, yo, skp, p4, k6, p3, yo, skp, p2, yo, skp, p4, k7
Row 21: k1, C6F, p4, yo, skp, p2, yo, skp, p3, C6F, p4, yo, skp, p2, yo, skp, p3, C6F, k1
Row 23: k7, p5, yo, skp, p2, yo, skp, p2, k6, p5, yo, skp, p2, yo, skp, p2, k7
Repeat rows 1 - 24 until desired length or you run out of yarn.