I used about 3-4 balls of Lion Brand Chenille Sensations and US size 8 needles. My scarf is 38" X 7".
When I make another, I would make it longer than the 38". The width can be adjusted depending on how wide a scarf you want.
Pattern:
Cast on 32 Stitches (or 24 for a thinner scarf)
Knit 4 rows in seed stitch
Keep First 4 and last 4 stitches in seed stitch
Repeat 1 - Seed 4, K4, P4, K4, P4, K4, P4, Seed 4
Repeat 4 times.
Then
Repeat 2 - Seed 4, P4, K4, P4, K4, P4, K4, Seed 4
Repeat 4 times
Keep this pattern up until you have knit 8 inches.
Then split your scarf in the middle by:
Seed 4, K4, P4, K4, add another ball of yarn and continue with P4, K4, P4, seed 4
Depending on when you decide to split you may be on a row that starts with P4, K4, P4, split.
Continue changing your pattern every four rows until you have knitted with a split about 4 inches long.
Then go back to one ball and continue on in pattern until 38" or longer depending if you want to wear your scarf inside your jacket (then 38" may do it) or outside in which you would want to make it longer. Make sure to end with another 4 rows in seed stitch. Fringe can be added or it can be left as is. Weave in your ends and you are done.