Firstly, you require a fabric which you will have to cut into two pieces according to the size which you want your pad to be. You can also use a towel for this purpose, folding it into layers, instead of having to cut it.
Now lay both pieces with the right sides facing one another. Maintaining a gap of about two inches, you need to sew the two pieces together after pinning the edges. If you are using a towel, use the side which looks better and pin the edges together.
Now turn this pad inside out, exposing the right sides of the fabric. The fabric needs to be pulled through the two-inch gap which you left in the beginning.
The pad will not be complete until you fill it up according to your preference. Usually people go for wheat, white rice, oatmeal, feed corn, buckwheat hulls, beans, flaxseed and cherry pits. Once you have chosen your filling, place it inside the pad until it is 3/4th full.
Having filled the pad to your desired level, you need to sew the opening close properly. Stitch the opening tight with a thick thread to ensure that the opening is permanently sealed.
After finishing you need to test the strength of the stitches to make sure that the filling does not spill out. If you sense some weakness in the stitches, it is recommended that you stitch some more in order to secure the pad properly.
Now before use, you need to place the pad in a microwave and heat for about 1 to 2 minutes. Before placing it on the skin, check the pad to make sure it is not too hot.