Here is a simple tutorial on how to make a beach coverup using a scarf. I bought this light scarf at Value Village for $3.99. It is double the size you see in the photo. I cut it half and serged the ends.
I then sewed the two edges together using a 1/4 inch seam allowance.
At the very top, I double folded a 1/2 inch hem and then sewed it in place all around leaving a hole for the elastic. I placed an elastic band through the hole and voila!