If you are wishing to connect with someone who is passed, it is helpful to think about the person or people in the spirit world before a reading. Thought is energy and the spirit world can sense your energy, and this will help to raise the vibration in making stronger connections possible.The more open minded and open hearted you are, the clearer the messages will be for you.
If you are looking to connect with one specific individual in the spirit world, I cannot guarantee that they will "show up" in a reading, though they usually do. To understand the work of a medium, think of the process of mediumship like two telephones. The telephone in the spirit world has a dial, and the telephone here in the physical world is only a receiver, without any dial. I can only receive the communication that the spirit world is willing to send at that given time based on their own free will.