I think that communicating with relatives or mediumship in general is in the hands of the spirits themselves. If they want to communicate with or through you then they will open your psychic channels. mediums such as the ones on tv have discovered the ability to keep those channels open all the time that they need them to be.
I would love to connect with my guides. My wife believes that her grandmother is looking after both her and myself but I'm sure there are other guides as well but sometimes I feel that they must be tearing their hair out over me as I'm sure I haven't listened to them on more than one occasion in my life.
Of course all this is speculation on my part as I have no evidence to back up my beliefs.