Yes, you can make the boomerang yourself, but it is pretty hard to do. You will have quite a hard time making the sword too. You can make them out of styrofoam. That is going to be the easiest material to work with. However, this won't be very strong. Another option is to make them out of wood. This is a lot harder and much stronger. You can also buy this online. This is not going to be so expensive.