In his book Peace is Every Step, Thich Nhat Hanh explains a procedure to transform our negative feelings, which I find very valuable. Here are the steps in the process:
1. Recognize each feeling as it arises. When a feeling arises, we acknowledge it. Fear is present. Anger is present. Hatred is present.
2. Welcome the feeling. Don't push it away. The way to learn about our fears, our anger, is not to repress them but to actually thank your fear, your anger, for being there for you. You've adopted them as a response for a reason, so thank them for what they do for you. Accept their presence.
3. Calm the feeling. Strong feelings can overwhelm our wisdom, so slow your breathing. "Breathing in, I calm my anger. Breathing out, I calm my anger."
4. Once the feeling is reduced in intensity, release it. Smile at your anger and allow it to depart, thanking it for visiting. Yes, really, smile at it. :) You'll be amazed at how much this helps.
5. Look deeply into the feeling, now that it is no longer overwhelming you. What is its cause? Is there an external stimulus to this feeling? What response of yours causes this feeling to arise? What internal causes are there? Ultimately, all causes are internal, as your feelings are totally based on your responses to stimuli. What effects are there to this feeling? What effect does it create in you? What effect does it have on others? Does your feeling cause suffering to others? Acknowledge it if it does.
Buddhism places great emphasis on this process because we say that our suffering is caused by us alone. Pain is unavoidable, but we habitually compound pain by our response to it, which causes us to suffer. Hence, we need a thorough understanding of our feelings, our thoughts, our actions. We can only eliminate suffering if we understand its causes.
In the book, Thich Nhat Hanh applies this process to negative feelings. However, I'd add that it is just as valuable to apply it to our positive feelings. When we are feeling loving and compassionate, we have the oppportunity to learn how we feel that way. This wisdom teaches us how to be more active participants in our lives; we can learn what causes us suffering and avoid it, and we can learn what causes us to feel love and compassion, and nurture those causes.