The basic fundamentals are taming the unruly mind and being mindful of our thoughts, speech and actions. While as much as possible, avoid destructive ways of thought, speech and actions while cultivating positive and constructive ways of thought, speech and actions. This requires taming the mind, by ridding it of confusion about reality and about behavioral cause and effect.
Buddha teachings are; Commit not anything negative at all; splendidly enact what is constructive; fully subdue your own mind.
Negative means something self-destructive, something that causes problems and unhappiness to others. Splendidly enact what is constructive means something that brings about positivity and happiness for all.
Meditation is the tool to fully subdue your mind. Meditation is a natural relaxation state of the mind. The proper way to meditate is just start, developing a practice over time. Do what works for you. Sitting in a chair or floor with good posture, close your eyes, take 5–10 slow deep breaths, following your breath. Your relaxing your mind so try not to think of anything. Just focus on a point in the front of eyes. You will find your thoughts drifting to problems just bring the focus back to the point in front of the eyes. The time you meditate is up to you.
The above describes the first step of Dzogchen,an esoteric tradition of teachings considered to be the highest and most definitive path to enlightenment by Tibetan Buddhism, known for the Rainbow Body. Buddha found enlightenment with the breath sitting under a tree. So with the will and wisdom, dzogchen becomes an incredibly profound and effective method for achieving enlightenment for the benefit of all beings. The fundamentals of Dzogchen meditation can be found here, and even may be the most powerful meditation technique.