These twenty instructions contain the very essence of all Yoga Sadhana. Karma, Bhakti, Jnana, and Raja Yoga will all come to one who follows them whole-heartedly. They are the unfailing keys to quick and effective development and culture of the physical, mental, moral and spiritual self of man.
Get up at 4 a.m. daily. This is Brahmamuhurta which is extremely favourable for Sadhana. Do all your morning spiritual Sadhana during this period from 4 a.m. to 6:30 or 7 a.m. Such Sadhana gives quick and maximum progress.
Sit on Padmasana (lotus pose), Siddhasana (adept's pose) or Sukhasana (any pose you like) for your Japa and meditation for half an hour, facing east or north. Increase the period gradually to three hours. Practice Sirshasana (headstand) and Sarvangasana (shoulderstand) for maintenance of health and Brahmacharya. Take light physical exercises as walking, etc., regularly. Do twenty rounds of easy, comfortable Pranayama (breathing exercises). Do not strain yourself while doing Pranayama.
You can repeat any Mantra (sacred syllable), such as pure Om or Om Namo Narayanaya, Sri Ram, Sita Ram, Sri Ram Jaya Ram Jaya Jaya Ram, Om Namah Sivaya, Om Namo Bhagavate Vasudevaya, Om Saravanabhavaya Namah, Hari Om, or Gayatri (a sacred Vedic Mantra), according to your taste or inclination, from 108 times to 21,600 times daily. Devotees of Christ may repeat the name Jesus or Hail Mary, Mother of Jesus. Parsis, Sikhs and Muslims may select a name or Mantra from the Zend Avesta, Granth Sahib or Koran respectively.
Take Sattvic food. Give up chillies, tamarind, garlic, onion, sour articles, oil, mustard, asafoetida. Observe moderation in diet (Mitahara). Do not overload the stomach. Give up those things which the mind likes best for a fortnight once or twice in a year. Eat simple food. Milk and fruits help concentration. Take food as medicine to keep the life going. Eating for enjoyment is a sin. Give up salt and sugar for a week or a fortnight. You must be able to live on rice, dhal and bread without any pickle. Do not ask for extra salt for dhal, and sugar for tea, coffee and milk. People taking a non-vegetaraian diet should try their best to gradually give up flesh-eating as completely as possible. They will be immensely benefited.
Have a separate meditation room under lock and key. If this is not possible then a corner of the room should be set apart with a small cloth screen or curtain drawn across. Keep the room spotlessly clean.
Study systematically the Gita, Ramayana, Bhagavatam, Vishnu-Sahasranama, Lalita-Sahasranama, Adityahridaya, Upanishads, Yoga Vasishta, Bible, Imitation of Christ, Zend Quran, the Tripitakas, the Granth Sahib and other religious books from half an hour to one hour daily, and have Suddha Vichara (pure thoughts).
Learn by heart some prayer - Slokas (prayer verses), Stotras (hymns) and repeat them as soon as you sit in the Asana before starting Japa or meditation. This will elevate the mind quickly.
Preserve the vital force (Veerya (seminal energy)) very, very carefully. Veerya is God in motion or manifestation (Vibhuti). Veerya is all power. Veerya is all money. Veerya is the essence of life, thought and intelligence. This instruction is not for bachelors only. Householders also must follow it as far as possible. They must be extremely moderate in their marital connections with their spouse. This is very important.
Do charity regularly, every month, or even daily according to your means. Never fail in this item. If necessary forego some personal wants but keep up this charity regularly.
Give up bad company, smoking, meat and alcoholic liquors entirely. Have constant Satsang (association with holy people). Do not develop any evil habits. Deliberately exert to develop positive virtuous qualities.
Fast on Ekadasi (11th day of the Hindu lunar fortnight) or live on milk and fruits only. Christians must fast on alternate Sundays, Muslims on alternate Fridays, and Parsis on a suitable day every fortnight.
Have a Japa Mala (rosary) around your neck or in your pocket or underneath your pillow at night. This will remind you of God. Twirl the beads during your leisure. You should repeat the Name at all times, whatever task you may be engaged in.
Observe Mouna (vow of silence) for a couple of hours daily. Do not make gestures and inarticulate noises during the period of silence.
Speak the truth at all cost. Speak a little. Speak sweetly. Always utter encouraging words. Never condemn, criticize or discourage. Do not raise your voice and shout at little children or subordinates.
Reduce your wants. If you have four shirts, reduce the number to three or two. Lead a happy, contented life. Avoid unnecessary worry. Be mentally detached. Have plain living and high thinking. Think of those who do not possess even one-tenth of what you have. Share with others.
Never hurt anybody. Ahimsa Paramo Dharmah (Non-injury is the highest virtue). Control anger by love, Kshama (forgiveness) and Daya (compassion). Serve the sick and the poor with love and affection. This is service of God.
Do not depend upon servants. Self-reliance is the highest of all virtues.
Think of the mistakes you have committed during the course of the day, just before retiring to bed (self-analysis). Keep a daily spiritual diary and self-correction register as Benjamin Franklin did. Maintain a daily routine and resolve-form. Do not brood over past mistakes.
Remember that death is awaiting you at every moment. Never fail to fulfil your duties. Have pure conduct (Sadachara).
Think of God as soon as you wake up and just before you go to sleep, and at all other times whether engaged in any work or not. Repeat His Name always. Surrender yourself completely to God (Saranagati).

This is the essence of all spiritual Sadhana. It will lead you to liberation. All these spiritual canons must be rigidly observed. You must not give any leniency to the mind.