There are elaborate methods described in the necronimicon but some common ones are meditation, the use of ouija, summoning, and in/evoking.
Most of those people will immediately jump and tell you not to even think about using but in my honest opinion I think as long as you know what you're doing, have done you're research, can perform and practice properly, and have standing respect for what you're getting into you'll be fine or at least know how to handle yourself.
If you look in the right places you can find information on the things I listed. Usually though you find it in covens because they can be touchy subjects for public (usually end in heated arguments).
Oh and I really don't think there is a 'spell' to make you communicate with them. I see it as a psychic ability. But if you're just communicating with one being, I don't see how you can call yourself a medium unless you opened the ability to communicate with all of the dead.
You just need to work on your chakra system, third eye, and I use crystals. Amethyst is a great psychic crystal for your third eye.
Oh and...
practise practise practise!
x
I agree iscorpio. Another thing you should do is make offerings to them such as coins food rum etc. This invites them and lets them know you want to talk to them. I also invite them to speak to me in my dreams but please remember always be respectful and say thank you. Sometimes just asking them to speak with you works too. -blessings, cielodrive69
it really depends on which views you have. To me that sounds more of a pagan view, but honestly I wouldn't be talking to ghosts any ways. Deceased loved ones? Yes. And remember, everyone has their strong and low points. Dreams don't work for me. But I'm great at consiouslly connecting to spirit.
I've spoken to deceased loved ones before, which now that I think about it is a bit different than talking to just any ghost. I think offerings are something more characteristic of spirits like fae or daemons than the dead. I learned to commune with the dead by reading Sylvia Brown, so I recommend her work.