Everyone has a different method that works for them, the standard 'crisscross applesauce close my eyes and focus' method won't work the same for one person as it does another.
For instance, my boyfriend is to a point where he is in near-constant meditation, his method allowing him to both meditate and stay quite aware of what's around him.
On the other hand, my method is to listen to the video above while doing a few minutes of Tai Chi to calm my energy and get it flowing before slowly sitting down and placing a metaphysical (between physical and spiritual technically) barrier with my own energy then using a small chant for a spiritual barrier - 'Spirit of Air, Spirit of Earth, Spirit of Water and Spirit of Flame, protect me in thy plane'. Both barriers are there to protect me from negative energy influences.
One of my brothers has anger issues and generally cannot use the standard meditation because he will fall asleep so I suggested a kind of meditation that would move his body while letting his mind go within - training a certain set of forms until he can do them without thought, keeping himself awake as he focuses within. He also mentioned that physical training is 'boring' to him and he prefers spiritual fighting to which I responded with 'fight your anger then, like it's another being'.
As for what meditation can do for a person, it can realign their energies, focus their minds, make it easier to access their inner self and the abilities of that self.
A while ago, I guided another Mythical to an 'energy shift' where they align their energies, through meditation, to match the energy of the form they wish to shift into, making it so any future shifting they would do would come to them easier. It succeeded and they have since been feeling stronger and have managed to partially shift physically with a bit less pain than previously experienced.
Another friend uses meditation to clear and cleanse their chakaras which can help one who has dark energy in them that needs to be cleared.
My boyfriend, when he meditates instead of sleeping, generally uses it to not only keep himself warm but can also sense the prescense of other people within a certain distance.
