So I went to buy couple more at the mall, but was not impressed with $20+ price tags. Instead I found seller FABULACE on Etsy and bought a couple pieces of knit jersey for about $3 a yard. The piece I cut up for this scarf was 1 1/2 yards long by 60" wide, so that's enough to make two scarves!
There are a million infinity scarf tutorials on the internet, but the ones I saw all involve hand sewing where the loop joins together. That's for lovely people who are patient and care about doing a really nice job. This thing will get all wadded up around my neck, so I'm thinking no one will see that I sort of cheated and did not care about doing a really nice job.
I cut a rectangle of fabric 22" wide by 1 1/2 yards long.
I folded it in half lengthwise with the right sides together. I sewed along the open edge to create a long tube.
To join the open ends together to form a continuous loop, on one end I turned the raw edges to the inside about 1/2". I stuffed the other end of the scarf inside the opening and pinned them together, then sewed along the pinned edge.