There are many different patterns online for using a pillow case to make into a reusable tote. The pictures aren't great, but here's a behind the scenes look at how I created this one.
I found a standard pillow case at the thrift store for a quarter a piece. I brought them home and washed and ironed them. I then cut off the finished (opened end) right at the stitching.
I sewed up the open end, leaving a small opening for turning.
Once turned, I whip-stitched the opening closed and that end because the inside of the bag by pulling the two sides apart and folding the seam I just made into the center of the other side. I need to take more pictures of this next time so it is more clear.
The fabric is now a bit smaller than half the size of the original pillow case. I turned the bag back inside out and sewed a small section of each inside "corner".
When turned back right-side out, it makes a nice corner to the bag, though the below picture is too blurry to probably see what I mean.
The part I cut off at the beginning was cut into two equal pieces and sewed into the middle of the bag, one on each side. Total time, aside from washing and drying was less than 15 minutes, including the ironing of the pieces as I worked it up.
I thought this bag would be a perfect beach tote!