A nice plump pillow can end up corners that stick out like a bunny ear, just because a pillow is so plump in the middle and nothing is really filling the corners. Using a pillow form is the best way to change pillows but a prime culprit in creating pillow ears.
- Taper the corners -- By tapering the seam line to take in fabric at the corners you will create a more fitted cover and avoid the ears. Putting the cover on the pillow form inside out, allows you to mark the wrong side of the fabric as to where to start tapering the seam. A very gradual and slight taper is all that is usually needed to maintain a "normal" pillow shape.
- Sew across the corners -- Just as when you sew a collar or cuff corner, stitching a few stitches across the corner, allows room for the seam allowance and allows a sharp corner.