Here’s a quick one I made. Approx 24” length by 14” across. Double sided, light layer of fusible. I just guessed on pocket size. Front & back right sides together, pockets inside & ties. Leave a few inches for turning, etc. i staggered diviiding the pocket stitching one in half and the other 1/3 & 2/3( larger pocket worked well for mail, magazines, etc.
if I were to make this again, I would have a velcro flap over one pocket.
This stayed in place well when putting in the car. Hope the picture shows up.