The Lord is attained without the least effort; he is worshipped by self-realisation alone. … The self is not realised by any other means other than meditation. If one is able to meditate even for thirteen seconds, even if one is ignorant one attains the merit of giving away a cow in charity. If one does so for one hundred and one seconds, the merit is that of performing a sacred rite. If the duration is twelve minutes, the merit is a thousandfold. If the duration is of a day, one dwells in the highest realm. This is the supreme yoga, this is the supreme kriyā.

— Yoga Vāsiṣṭha (tr. by Swami Venkatesananda p. 255)

What is meditation?

Meditation is not a practice; it is not the cultivation of habit; meditation is heightened awareness. Mere practice dulls the mind. heart for habit denotes thoughtlessness and causes insensitivity. Right meditation is a liberative process, a creative self-discover which frees thought-feeling from bondage. In freedom alone is there the Real.

— J. Krishnamurti (source)

Meditation doesn’t imply merely sitting in a posture with eyes closed. Meditation, in essence, means heightened awareness, being intensely aware of the present moment. This heightened awareness comes about only when you are not making any effort. It comes about with the acceptance and awareness of the present moment as it is. If you are in such a state of pure awareness, you are in meditation irrespective of what you are doing. In Yoga Vasishta it is said that, “While doing whatever one is doing — seeing, hearing, touching, smelling, eating, moving, sleeping, breathing, or talking — one should realise one’s essential nature as pure consciousness. Thus does one attain liberation.”

Of course, if you think that sitting in a posture with eyes closed helps you get to the state of heightened awareness, you can definitely practice that.

How to meditate?

When you sit down to meditate, tell yourself that at this time “I want nothing”. The second is to tell yourself “I do nothing”. The third sutra (principle) is “I am nothing”. Do not think that you have to meditate, just sit and be hollow and empty. You do not have to make any kind of attempt. These three sutras are very important.

— Sri Sri Ravi Shankar (source)

What is the truth?

‘I have nothing to do with sorrow, with actions, with delusion or desire. I am at peace, free from sorrow. I am Brahman’ — such is truth.

‘I am free from all defects, I am the all, I do not seek anything nor do I abandon anything, I am Brahman’ — such is the truth.

‘I am blood, I am flesh, I am bone, I am body, I am consciousness, I am the mind also, I am Brahman’ — such is the truth.

‘I am the firmament, I am space, I am the sun and the entire space, I am all things here, I am Brahman’ — such is the truth.

‘I am a blade of grass, I am the earth, I am a tree-stump, I am the forest, I am the mountain and the oceans, I am the non-dual Brahman’ — such is the truth.

‘I am the consciousness in which all things are strung and through whose power all beings engage themselves in all their activities; I am the essence of all things’ — such is the truth.

This is certain: all things exist in Brahman, all things flow from it, all things are Brahman; it is omnipresent, it is the one self, it is the truth.

(Yoga Vāsiṣṭha (tr. by Swami Venkatesananda, p.233)

Whether one is a knower of truth or ignorant of it, powers like flying in the air accrue to one who engages himself in some practices . But the sage of self-knowledge has no desire to acquire these. These practices bestow their fruit on anyone, for such is their nature. Poison kills all, wine intoxicates all, even so these practices bring about the ability to fly, etc., but they who have attained the supreme self knowledge are not intenrested in these, O Rāma. They are gained only by those who are full of desires; but the sage is free from the least desire for anything. Self knowledge is the greatest gain; how does the sage of self-knowledge entertain any desire for anything else?

— Sage Vasiṣṭha (The Supreme Yoga, a translation of Yoga Vasishta by Swami Venkatesananda, p. 216)