With this, you not only are able to see ghosts,energy(gravity,magnetism,electricty,etc.), but can see the future and past, and so much more. Clairvoyance is very closely related to Precognition and retrocognition, and remote viewing as well.
To be able to have this, all it takes is either 1;opening your third eye, or 2: practicing visualization.
People with high visualization skills are more natural at this and grasp it easier and faster.
Here's how to open 3rd eye chakra(between your eyebrows and is an indigo color)
1. First relax and meditate for 10-15 min.
2. Visualize a bright indigo colored whell or vortex swirling clockwise bettween your eyebrows, glowing ery bright.
3. Focus all your attention onto it. praactice everyday, and you will know its open.
or....
Heres how to imagine/visualize
1. Just relax and meditate
2. Get a small object and for 30-45 sec. look at all its dimensions and look at all its sides.
3. When times up, close your eyes and try your best to form a mental image in that black space behind your eyelids. It will be hard for some after their first few tries, but if you keep at it for about 2 or so weeks. Without giving up, you will get it.