You can follow the designs of pillows from a number of places on the Internet, and you can use them on your pillow covers. You can definitely find a number of designs, and it is advisable that you always go for the designs, which are quite easy for you to do.
Designs, where you will have to follow a straight process of knitting are quite helpful compared to those, which are having bends within them. You can follow a design, which consist of multiple squares, where each square has two colors, one at the outer one, which is deep, while the inner one will be light colored.
But for the next square, the opposite directions will follow. In the same way, you can make a beautiful design for your pillow, which is quite simple but very beautiful. Apart from it, you can also use a number of other colors, but it will need only two colors.