There are two types of people, radiators and drains. Radiators give energy whilst drains sap energy. Radiators love other radiators and drains love radiators even more. Radiators give drains a boost and help to make people feel better about their situation or themselves.
A sincere complement costs nothing and yet is incredibly valuable to the recipient. It will also do wonders for your own self esteem and confidence as you see the pleasure you are spreading.
Be uplifting to at least one person a day. Be sincere and do it for the pleasure it gives the other person rather than the fact that you may gain from it. Once you get in the habit of one a day, feel free to keep increasing the number!