Before Grant was born I made him a jingle ball and he still has it a year later and loves throwing it all over and shaking it to hear the little jingle it makes. I used the free pattern from Grand Revival (the link is on the right side bar). You can make three different sizes, I made the medium sized ball.
Before sewing the stuffing opening closed just throw in a few little jingle bells you can get at Walmart, Joann's, or Hobby Lobby. With Grant's I bought the small bells and it took about 3 or 4 before the jingle was loud enough to suit me, so you may want to buy the larger ones.
I used scraps of fabric for these I already had in my stash along with stuffing I had, so the cost was nothing, and they are super cute when your little one is playing with them.