My teacher Rosalyn Bruyere used to say "don't be doing healing on someone you don't like". That is - if you want to continue to dislike them.
There's something about touching another person and channelling healing energy that opens my heart to the recipient. It is always interesting to notice my judgements of someone - and then as soon as I hear their story, and especially once I touch them with Reiki or other forms of energy healing, the judgement melts. I move from judgement to compassion and caring - and love.
Most of us are so quick to judge or anger, and much of it is based on assumptions we make up about the person, or their motivations. We usually don't know what's underneath actions or attitudes that we don't like.
I am a big proponent of forgiveness. I love the explanation that Carolyn Myss offers (or did many years ago during a workshop I attended) about holding onto anger and forgiveness. She said that every morning, we awaken with a certain amount of energy for our day, like having a certain amount of money in the bank. When we "spend energy" by holding onto anger, it depletes our energy supply. We have less energy for ourselves to enjoy our day! It does not hurt the person we are angry at - it only hurts us!
I see forgiveness as letting go of the person and situation that we are upset about. We don't necessarily want to invite them to dinner. We may never see them again. But as we let go ("give forth" = "forgive"), we free ourselves to be happier and healthier - and to have more energy for us.
Reiki is the energy of unconditional love. Every time you give Reiki, you receive Reiki. That is, it fills you before it comes through you and out of your hands. So, as you touch someone you are not liking (or someone you ARE liking), you are filled with unconditional love, and that is what you are sharing with the recipient. Reiki makes it pretty difficult to stay angry and judgmental!
Another lovely aspect of Reiki is that you can use it for remote or distant healing. You can send Reiki healing to a relationship (what I call "the space between people"). This is another great way to let go, forgive, love, and - for relationships that are already happy, to add even more love and happiness.