Many people have asked me this same question so far and i thought i would write about it hopefully it would help you to understand some things if you want to open up to seeing and hearing spirits and to understand a little bit more
First: what you need to do or what i suggest is that you find a nice quiet space to sit down with as minimal distractions as possible. this will help you focus on what you need to do; Second sit down however makes you comfortable and close your eyes and focus on the middle of your forehead and visualize a closed eye in the middle of your forehead and a zipper from your hair line to the back of your head going in a straight line to the back of your head.
next: have your eyes closed and focus on the "third eye" in the middle of your forehead and visualize this eye starting to open like you would your own eyes but very slowly when you have this visual hold onto it for a few secs you will feel a lil sensation in the spot that you are focusing on this is normal many people i have talked to feel dizzy this is also normal
onto the zipper: when you are done with your third eye i want you to turn your attention to the zipper on your head visualize slowly opening the zipper to the back of your head you will feel the lightness from this visualization what this does it opens up the means in which for you to receive information from spirits like visions and other information once you have visualized the zipper being opened i want you to focus on the feeling for a few secs you have now opened yourself up to see and hear spirits
WARNING: if this gets to be too much it is easy to close yourself off just do the visualization in reverse with the zipper being closed and the eye shutting I myself have had many times where i was too scared and closed myself off
I hope this has helped but its only the beginning there are more to come