The following teachings of St. Hilarion of Optina were taken from Living Without Hypocrisy: Spiritual Counsels of the Holy Elders of Optina, Holy Trinity Publications, 2005:
Anger
If you feel that you cannot control your anger, remain silent, and for the time being, simply say nothing, until, through continuous prayer and self-reproach, your heart has become calm.
Caution in speech
During conversation with others it is no hindrance to be cautious in speech, and at the same time one can retain the Jesus Prayer in the mind.
Relations with neighbors
One must strive to have a good opinion of everyone. Only God is the Knower of hearts. We cannot infallibly judge people.
Repentance
In case of a fall of some kind in deed, word, or thought, you should immediately repent and, acknowledging your infirmity, humble yourself and force yourself to see your sins, but not your corrections. From examining his sins, a person comes to humility and acquires a heart that is broken and humble, which God does not despise.
Prayer
We must not attribute miracle-working power to our prayer; we must not think that what we ask of the Lord is always fulfilled. This thought comes from pride and leads to deception.
God does not demand undistracted prayer from beginners. It is acquired with much time and labor, as the writings of the holy fathers say: "God grants prayer to those who pray...”
Thoughts
When having thoughts of self-praise, we must look at our sins and remember that without the help of God we can do nothing good and beneficial, we have only sins and infirmities.
Praise
Pay no attention to praise and fear it; remember what one of the holy fathers says: "If someone praises you, expect reproaches from him too."
Reconciliation
If you reconcile your own heart towards someone who is angry at you, the Lord will tell his heart to reconcile with you.
Self-will
By desiring to live or die in this place, but not that one, we establish our own will, we desire to fulfill our own desires, which we must not do. Do not pray to the Lord for any such thing, but pray that His holy will may be fulfilled in us.
Sorrows
Let us endure for a little while and we will receive eternal blessedness. Let us consign to oblivion all earthly pleasures and joys—they are not for us. It has been said: Where our treasure is, there our heart will be (cf. Luke 12:34), and our treasure is in heaven; therefore let us strive with all our heart for the heavenly Fatherland. There all our sorrows will be turned to joy; abuse and disparagement—to glory; sorrows, tears and sighs—to consolation; sicknesses and toil—to everlasting peace without pain.
When sorrow comes to us, we must await consolations, but after the consolation, we must again await sorrows.
We cannot live in such a way that no one grieves or offends us, for the Apostle Luke writes: we must through much tribulation enter into the kingdom of God (Acts 14:22), and bear ye one another's burdens, and so fulfill the law of Christ (Gal. 6:2). Let us therefore ask that we may bear sorrows with self- reproach and humility and not be overcome by evil, but overcome evil with good, and with the Prophet say: With them that hate peace I was peaceable (Ps. 119:6).
You are bored because you think too much about yourself and you censure those who are weak.
Spiritual welfare
In the pure writings of the Holy Fathers, we see that he who desires to cleanse his heart of the passions must call on the Lord for help—this is so. We cannot say the Jesus Prayer without our thoughts being plundered. With beginners, God does not demand undistracted prayer: it is acquired with much time and labor. As the writings of the Holy Fathers say: "God gives prayer to him who prays,” thus we must nevertheless continue to pray, orally, and with the mind.