Thread a needle and knot the end of the thread
Place the button on the fabric where you want it
Push the needle up through the fabric and one buttonhole
Pull the thread through and down through the opposite buttonhole
Repeat through the same two holes several times
If the button has four holes, sew the other two holes the same way
Keep the stitches snug but not too tight
Wrap the thread around the stitches under the button a few times to make a shank
Push the needle to the back of the fabric
Make a few small stitches on the back to secure the thread
Tie off the thread and cut the excess