meditation, when you relax they can contact you in this state. they have been known to enter your dreams though if this was recent i wouldn't trust it. skrying, ask/think questions and images should appear to answer them. automatic writng where you go into a trance like state allowing the spirit to take over and write something for you. pendulum, where you get a crystal attached to a string and let the spirit move it for 'yes', 'no', 'don't know', or 'don't want to answer'.
i believe divination tools such as runes and tarot have been used, but i have never used them for this reason so i can't say for certain. you would have better luck if you have a photo, some of their belongings and/or perfume/cologne/favourite scent on hand to specify who you wish to speak with. there are other methods, those are more common ways.