This pillow is easier than it looks, with my method of attaching the buttons without ANY sewing! If you're like me, you don't relish the thought of sewing on tons of shank buttons...but now you don't have to.
Start with a fabric that has about a 2" to 3" repeat. The awesome fabric you see above is called "Ghastly Forest" by Alexander Henry. They have the best Halloween collection this year! Since I used the small, pale blue pillow form from IKEA (only $1.99!) my square was cut at 13.5".
Cut a piece of heavy, fusible interfacing that is 1/2" smaller in length and width than your square (Pellon Decorbond #809 is my favorite). Fuse interfacing to backside of fabric, leaving 1/4" border around all edges of fabric without interfacing (to reduce bulk when sewn together).
Place the fabric covered buttons where you want them to go, leaving at least 2.5" with no buttons all the way around or you'll have a terrible time trying to sew the pillow together later on. I used 2 different sizes of buttons and alternated them in rows.
Use a marker or fabric pencil and carefully put a dot beneath each button where the shank touches the fabric.
Moving one button at a time, carefully poke through the fabric+interfacing at each marked dot with a tiny Xacto knife or other very small, poky tool. If the hole/slit is too big, you'll struggle later on. Gently push/coax the shank of the button through the fabric+interfacing. If the hole is small, the button will stay in place for now.
When all buttons are pushed through, carefully turn fabric over to access all the shanks poking through the backside.
Using a hot glue gun, squirt a small but generous blob of hot glue around each shank, making sure that the glue oozes inside the little loop of the shank to hold it in place and keep the fabric from fraying around the hole. Let harden thoroughly.
Cut 2 strips of border fabric which are 1.5" wide. Stitch to sides, press, and trim.
Add 2 more strips to top and bottom of pillow. Press and trim.
For the backing, cut 2 rectangles that are the same width as the pillow front but the length is determined by adding about 3" to whatever the half point is on the pillow. In this case, the pillow front is a 15" square. I cut 2 rectangles at 15" x 11" (11 = 8 + 3).
Press under 1/4" of one of the 15" edges on each rectangle. Press under again to hide the raw edges. Stitch along that "hem".
Place pillow front face up on table. Place the 2 rectangles face down, aligning outer raw edges so that there is about a 3" overlap over the middle of the pillow. Pin in place all around outer edge of pillow.
Stitch 1/4" all the way around, clip corners to reduce bulk. Turn right side out, press edges.
To create flange, "stitch in the ditch" all the way around the pillow where the border meets the main fabric. Insert pillow form and you now have one very cute pillow!
Disclaimer: this is where I need to write about not having this pillow in a baby crib or within reach of a small child, due to the very remote chance that the buttons could come loose and be a choking hazard. But you already knew that, right? Enjoy!