I used Caron Simply Soft and a K crochet hook (which is bigger than the recommended hook, but I don't really care).
R1: Chain (CH) 180 (or whatever length you want, so long as it is a multiple of three).
R2: Turn. In the third chain from the hook, double crochet (DC). DC all the way to the end. Turn again.
R3: CH 3. Skip the first two chains. Then, in the third chain from your hook: DC1, CH1, DC1. Continue skipping two chains and DC1, CH1, DC1 across the row. Finish the row by skipping one, and DC1 in the final chain.
R4: CH3. Then, in every CH1 space from the previous row (the spaces with downward facing triangles), DC3. Finish the row with a DC1 in the final chain.
Repeat R3 and R4 until the scarf has reached the width you like.
For the final row, single crochet across.
Then, sew the ends of the scarf together, and you are done.
As you can see, I changed colors on mine, but you don't necessarily have to. I kind of like how it looks though. If you are going to change colors, do so at whichever point you choose. There really is not a right or wrong here.
Have a great weekend!