I use to make clothing a lot and when making costumes, on an occasion I would run out of time and /or ideas to get it done the right way.
I found that if I zigzag the edge of the fabric (seam allowance), then roll it under and sewed it in place, it worked out OK. At least it held up until I could find what was needed to make it permanent, if it was necessary to use the costume again later. Most of the time they were used only one time so it was never a problem.