Most effective meditation techniques to develop empathy, love and compassion for others?

I recommend you metta meditation. It is simple meditation you can do even when you are traveling in a bus etc. Basically what metta meditation does is, it help us to think about others well being and betterment with wishing their success. We can do metta meditation direction wise or group wise. Read meththanisansa sutra and karaneeyametta sutra for further information.

First thing a person do in meththa meditation is hope the well being of himself

May I be happy.
May I be at peace.
May I live with ease.
May I be free from suffering.

Then you can move direction wise or group wise and wish well being of other people.

All the people in the direction of north,
be happy.
be at peace.
live with ease.
be free from suffering.

This way you can spread metta for all 10 directions or for parents, relations, neighbors ,people who are friendly, people who are neutral, people who are hatred etc....

From this meditation you can earn 11 benefits during this life..read them on those sutras.

In practical mannaer you can spread metta at any time.. for example, when you are going to work in early morning.. hope all people who are walking to work... going on bus.. going on train etc may they all happy today.. may everything they do be successful..etc.

When you see a person with a illness sadness or any problem, spread metta to him... may this person be recovered from the illness..may this person happy and peaceful etc....

When you hear of see an ambulance is passing by..in your mind think may this person feel well, may this person recover from illness.. may this person live long etc.

Developing these kind of thoughts will automatically brings those people's love , affection and kindness to you back too.

You can try metta meditation.

There are some guided metta meditation YouTube videos:

• Ajahn Brahm's Guided Metta Meditation
• Bhante Gunaratana's Guided Metta Meditation
• Thanissaro Bhikkhu's Guided Metta Meditation
• Matthieu Ricard's Guided Metta Meditation
• Ayya Khema's Guided Metta Meditation
• Mindah-Lee Kumar's Guided Metta Meditation

I cannot make a recommendation from the list above. It's up to you to find the one that you like.

There are different ways of going about this goal.

A problem with merely reciting the standard formula could be that it may feel like internally, you are actually experiencing the opposite intention.

Not being satisfied with oneself, even feeling aversion towards oneself, is quite common, especially in many Western cultures, and to extend metta from that position can be very difficult. The same thing is true when there are people you do not actually like, or even feel strong aversion or hate towards.

Personally, I suspect just reciting, going against one's actual experienced intention in the present moment could be counter-productive.

There are other methods to try.

You may first want to consider if there is anything or anyone that actually does bring up a sense of compassion and a wish for well-being inside of you.

Ajahn Brahm provides various suggestions: perhaps babies? Perhaps kittens or puppies? Some other animal? Perhaps somebody who showed you love and care when you were a child - one of your parents, one of your grandparents, etc.

Whatever or whoeever it is, is not so important, with the caveat that somebody you have been sexually attracted to is probably not the best choice.

The point is to find the feeling and amplify it as much as you can, before you start to extend the metta.

You can also use logic to strengthen your resolve. You can imagine what your situation would be like, and by extension, what the world could be like if people genuinely wished everyone else well.

Finally, there is a "backwards metta hack" that a kind monk taught me.

He explained that for him, metta had been the biggest challenge in his practice. He had a miserable upbringing and major problems with depression, even suicidal ideas, before he was introduced to Buddhism. So when he started out, he simply could not do it. He just couldn't find the feeling within himself.

However, as he started to learn how to calm the body and mind through meditation, he would experience increased peace and well-being within himself, and had a breakthrough at one time, as he was coming out of a very peaceful meditation and felt very calm, very soft and yet very clear and bright. At that moment, something inside of him clicked: 'What if I can radiate this state?' - and then he started the metta meditation. Immediately, it felt genuine.