I adapted a pattern from my book with Janelle MacKay, On the Go Bags, and I wanted to share how I you can do it, too!
This is the Cart or Stroller Caddy pattern, designed by my good friend Veronica. The original pattern has pockets on each side, so you can store coupons, a shopping list, a drink, pens, baby gear, and more, and easily hang it on the handle of a cart or stroller. It has Velcro at the top to keep it attached.
Because I knew this would be one-sided and would be staying in place, I only made 2 instead of 4 pockets and divided the backing dimensions by 2. I also sewed two buttonholes in the top with my Baby Lock sewing machine (so easy!) and sewed a 4-fold strap (fabric strip was about 5" wide and 18" long) to insert through the holes and tie around the headrest of the car seat.
Like this fabric? This fun raccoon print and the coordinating dots are from the Garden Party collection by Katy Tanis for Blend Fabrics, and you can get the full pattern in On the Go Bags!