You will be crocheting the shrug in one long panel, using 3 colors in a granny stitch pattern. You can decide which yarn colors to use for your rows. For symmetry, try to use the same mirrored stripe color pattern for both sides of shrug.
Next, you will block the panel.
Lastly, you will create two long sleeves by seaming together sections of the long edges of the panel, near where you want your arm holes.

Tips offered on how to adjust size.