I use my tarot quite frequently to communicate with those that have passed on.
I guess I could just tell you what I do. I mostly do these readings at night when everything is still. I don't have a reason for that I just prefer the night time. Then I light candles or turn down the lights. Sometimes I do a spell but not all the time.
Before I am ready to begin, I ask for the spirit by name and invite them to sit with me. I also always have an empty chair nearby. Again, there is no reason for this as they usually don't sit down.
I will only read for people that are tied to me or the person I'm reading for. Someone they knew, not just some random person or celebrity. I don't see anything wrong with doing that, I just prefer not to.
Usually I get images or phrases that come into my head, which is how I know I'm tied to the right person. For instance, say I get an image of a dance hall and my sitter confirms the deceased was a dancer. Little things like that come through, with much practice! I also (sometimes) am able to see the person and describe them in detail.
But also, I've found that if it too soon or too far from their date of passing it is harder to keep the connection. But I have had success with a large variety of time frames.
My advice to you is practice, work up a spread before you begin and just keep on at it.
You can start with this spread here.
But I changed the first question to, "What is it like where you are right now?" I also would try to stay away from yes or no questions with the cards, you could always use a pendulum for that too.
I hope that helped. Good luck!