For fun, I like to summon the dead.
The dead like to be flattered, so you have to praise them. For instance, if you want to call up a Goddess, you always have to CHANT her appraisal. Goddesses are very hard to please, you see. But it's not impossible. Okay, so this is how it goes. All you need to do is get on your knees (and you might want to keep a bang full of chocolate covered pretzels handy, just in case) and sing to her. And ta-da she will appear before your eyes.
This is what my girl friend sang once:
"Lin! Innin, Innana, Nana, Nut, Anat, Anahita, Istar, Isis. Goddess of many names, oldest of the old, who walked in chaos and created life, hear us calling you back through time, before Jehovah, before Christ, before men drove you out and burnt your temples, hear us, Lady, give us back what we were, give us the history we haven't had, make us the women we can't be."