I like to put my phone inside a "sock" before I throw it in my bag which has my keys and change floating around in it. I had this fabric left over from my living room ORC redo.
This took less than 20 minutes. I leave the hems exposed and because I'm sewing with wool I go with the fraying and use it to my advantage. The sides are cut with pinking shears, but will eventually fray like the top. The stitch at the edge prevents the fabric from fraying down to nothing, like Weezer's sweater.