How exactly are you supposed to use a ouija board. ive heard it is safer to recite some soft of prayer before you have a go. do homemade ouija boards work and if so can a person be "possesed" by using one by themselves. I have tried to use one once and it resulted in nothing.
Is it all in the mind or do they really work?

It's completely and totally in your mind. Your subconscious mind causes your hand to move, making it appear as if you are not controlling it. This is known as ideomotor action. In short, muscular action can be taken without conscious thought. Therefore, it may seem as if something paranormal is happening.

There is no evidence whatsoever to support the idea that a person may end up possessed by using one.