It is very common to see people realigning their priorities after a near death experience or surviving a cancer. Things like money, career, fear of the future or anxiety don't bother them as much as before.
In Buddhism how can one try to develop the same kind of behave? Only through meditation? Any specific meditation method to do it? (I thought about something related to death and impermanence, but it has to be something really powerful to achieve similar results)
The ancient extinct Kadampa school of Tibetan Buddhism (not the NKT, New Kadampa Tradition, which is an unsanctioned "breakaway" school) practiced mindfulness of death. Their motto was:
Base your mind on the Dharma
Base your Dharma on a humble life
Base your humble life on the thought of death
Base your death on an empty, barren hollow.
"The Words of my Perfect Teacher" by Patrul Rinpoche explain this practice in the following way:
While standing up, sitting or lying down, tell yourself: “This is my last act in this world”, and meditate on it with utter conviction. On your way to wherever you might be going, say to yourself: “Maybe I will die there. There is no certainty that I will ever come back.” When you set out on a journey or pause to rest, ask yourself: “Will I die here?” Wherever you are, you should wonder if this might be where you die. At night, when you lie down, ask yourself whether you might die in bed during the night or whether you can be sure that you are going to get up in the morning. When you rise, ask yourself whether you might die sometime during the day, and reflect that there is no certainty at all that you will be going to bed in the evening.
One Kadampa would always turn his bowl upside down when going to bed, and would not cover the hot ashes to last until morning. When asked why, he answered: "I really cannot say if I will wake up tomorrow".
Besides the ongoing mindfulness of death, there is also a formal meditation on death, which involves contemplating three points:
Under the 10 recollections there is a Kammaṭṭhāna which is recollection or death. This is can be used to develop spiritual urgency. This is similar to the near death experience, which changes the priories in a person. Upajjhatthana Sutta and related Suttas discuss in more detail.
In my opinion, you should place the attention on the spot (between your nose and upper lip) and start the breath meditation upto the 1st 3 steps in the 1st tetrad. Then with each in and out breath contemplate you might not live to have the next breaths. You are growing older with each breath passing away. You do not know what calamity (death, illness, accident, death or parting of a loved one, etc.) might befall you in the next moment. This fuels some level or urgency either spiritual or in other activities in life.
