Before we start on how to develop bodhicitta. We should know what is bodhicitta and why is it so important.
Bodhicitta is the wish to attain enlightenment (become a Buddha) for the benefit of all sentient beings.
It is the source of all success, whatever dharma doors you practise, if you have bodhicitta, you will progress and succeed very fast, but most importantly, with bodhicitta, your practise will benefit more sentient beings.
Some reflections by the saint Shantideva:
"Whatever joy there is in this world
All comes from desiring others to be happy,
And whatever suffering there is in this world,
All comes from desiring myself to be happy.
But what need is there to say much more?
The childish work for their own benefit,
The Buddhas work for the benefit of others.
Just look at the difference between them!"
Without bodhicitta, one is not really practising the mahayana buddhism, even if he does chanting of mantra, the benefit will be relatively smaller.
If one's main goal is for individual liberisation from samsara, that is considered hinayana practise. Personally, I don't call it theravada because there are many bodhisatvas in the theravada school as well.
With bodhicitta as the motivation of an action, even scolding a person will give you merit.
Below are the methods to generate bodhicitta:---------------------------------------------------------------
The '4 Point Mind Training' is based on cultivating four realisations:
1. Equanimity: One can cultivate the realisation that all sentient beings are equal in wanting happiness and not wanting suffering. Beings cannot really be divided into friends, enemies or strangers because friends may turn into enemies, enemies may become friends, and strangers may become friends or enemies.
2. Faults of self-cherishing: a consequence of karma is that self-cherishing is the only cause of my problems.
3. Good qualities of cherishing others: a consequence of karma is that cherishing others is the cause of all happiness.
4. Exchanging self & others: being intelligently selfish, by continually trying to put oneself in the place of others, and then acting.
The '7 Point Mind Training' is based on cultivation in 7 steps:
1. Equanimity
2. All sentient beings have been or, at least, could have been my mother as I have lived innumerable lives.
3. Remember the kindness of your mother in this life, all she did for you, the problems she went through to take care of you.
4. Would it be great if I could repay her and all previous mothers' kindness.
5. Generate great love: may all mother sentient beings have happiness and the causes for happiness.
6. Generate great compassion: may all mother sentient beings be free from suffering and the causes for suffering
7. I should give up all self-cherishing and egoism, and work to bring them happiness and release them from their suffering: therefore, may I become an omniscient Buddha, as he is the perfect doctor to cure the suffering of all mother sentient beings.