My day revolves around these things. I find that giving someone a compliment, and receiving a smile in return is one of the best things in the world. Or receiving a compliment, that's just as great.
For example... Today, there was a lady in a wheelchair. On my way on the bus, I said to her "I really like your hair, it's very pretty and soft looking." She smiled, and I continued to the back. On my way out, she stopped me, and said "Thanks," with a huge, warm, smile on her face. I know it's a bit corny, but it made me feel really good to know that I made her day, or at least made her happy for a bit by saying one little thing.
Or even smiling at someone. Isn't there a saying like "one smile can turn to a million" or similar. I really believe that, and when I get a smile back, that's a good feeling.
I don't go way out of my way, but at least once a day (most days a lot more than that) I try to compliment someone, and I smile at most everyone. It makes me feel good, and I know it makes some others feel good, too. Does anyone else do something similar, or at least identify with part of what I said?