Examine your character. Pick some distinct defect in it. Find out its opposite. Let us say that you suffer from irritability. The opposite of irritability is patience. Try to develop this virtue by meditation on the abstract virtue of patience.
Regularly, every morning, sit down at 4 am in padmasana or siddhasana in a solitary room for half an hour and begin to think on patience, its value, its practice under provocation, taking one point one day, another on another day and thinking as steadily as you can, recalling the mind when it wanders.
Think of yourself as perfectly patient, a model of patience and end with a vow: “This patience which is my true self, I will feel and show from today.”
For a few days, probably, there will be no change perceptible. You will still feel and show irritability. Go on practising steadily every morning. Presently, as you say an irritable thing, the thought will flash into your mind, unbidden: “I should have been patient.” Still go on with the practice.
Soon, the thought of patience will arise with the irritable impulse and the outer manifestation will be checked. Still go on practising. The irritable impulse will grow feebler and feebler until you find that irritability has disappeared and patience has become your normal attitude towards annoyances.
In this manner, you can develop various virtues such as sympathy, self-restraint, purity, humility, benevolence, nobility and generosity.