How To Setup Swing Party How Can I Practice Baseball Alone?

How can I practice baseball alone? - how to setup swing party

I do not really play anyone, but my half-brother, who is lazy and does not want to go with me about 15 minutes. I prefer a T-shirt and no wall around the corner or against something. I have a network of baseball. Is there something I can use or install to improve my skills? I've just seen my training and swing in a mirror to my mechanic. That was all. Any help and / or ideas?