It took me three hours last night to finally get a Boppy cover that fit and stayed closed. My first attempt was to create a regular pillow fold a little left of center. The concept was similar to how you'd make a slipcover for a regular square pillow but I could only get one side on. There wasn't enough give in the fabric to allow for room to stick the other side in. Thankfully I had used some mediocre fabric that can still be salvaged for something else.
I picked up this fabric on my trip to California in September. It's from one of my favorite quilt shops in Old Town Clovis. Someone is going to ask me who designed it but I've already thrown away the selvedge and can't remember. My apologies.
I used the fit from this tutorial after trying something else. I opted for vintage buttons instead of Velcro or snaps as the tutorial suggests and decided to use only one fabric rather than a soft fleece or chenille on the back. I didn't actually trace the pattern from the tutorial, just the concept of a fold over at the top, so I can't attest for the pattern's fit.
To get my shape I laid the pillow down on some fabric and gently pulled the fabric up along the sides and cut just above where the middle seam on the pillow would've been. It's a really rough way to get a good shape but it all pulled to fit. I had to take it in on one side to get things just right but it was a simple fix.
I should probably try to make another one for when this one gets baby juice on it but I'm not sure I've got the patience for more button holes at midnight. If you've seen another Boppy cover tutorial that worked for you, feel free to share. The best option may be to reuse an old cover as your pattern and work a zipper in. It's a great way to add another personal touch to the cache of baby accessories that make life with a newborn much easier.