What you need:
7 black candles (optional)
Inverted pentagram amulet (optional)

Place the black candles in a circle around you if you are using the candles (candles GREATLY help; though they are not required, if you're a beginner please use the candles). Light the candles clockwise, sit in the middle of the dark room

Close your eyes and meditate but instead of clearing your mind picture the spirit you are trying to contact, if it is no one in particular, just picture random spirit. Meditate this way for about 15 minutes. Blow put the candles in counter clockwise order.