For me, the best way to use the cards for this does not require a spread. I simply ask "Who was Clara in life?" Then I shuffle, and pull a few cards. What I see in those cards will give me a good handle on Clara's personality and energy. I might ask further questions, such as, "What was the relationship between Clara and my client all about?"
I use this same sort of dialogue throughout the reading.
Sometimes, there are issues about the death itself. In this case, I will use the dialogue method to pull cards in answers to questions such as "What did Clara experience at the moment of death?" and "Who was there to greet her from the other side?"
Then, I focus on the deceased (in this case our mythical Clara) as the deceased is now. I ask questions like "What is Clara doing now?" and "Who is with Clara now?"
Then I ask this question, directly of the deceased. "What message do you have?"
It is ok to ask specific questions of the deceased as well, and determine the answers by continuing to dialogue with the cards.
If you conduct this sort of reading for yourself, simply focus on the person you wish to contact. Breathe slowly, keeping your focus. Then you can simply start the conversation, asking questions and pulling cards to get your answers. Understand that your loved one is guiding the cards that come up, and inspiring your interpretation.
In this way we see that tarot is a language we share with the spirit world.
Sometimes we seek communication with ancestors or other people that we did not know in life. The process in that case would be basically the same.