Generating compassion for others will result in a significant increase of your own happiness.
For three minutes, think of someone who is suffering.
They could be suffering from physical pain or simply stuck in a bad situation.
Relate the suffering to yourself.
Recognize that that individual has the same capacity for experiencing pain, joy, happiness, and suffering that you do.
As you feel the compassion rise within you, focus your mind on it.
You will arrive at the conclusion that you wish for that individual to be relieved of their suffering. Focus your mind on this conclusion, and try and center your mind in this compassionate and loving state.