In many self help programs (including our own), positive affirmations are repeated throughout the program in order to re-enforce the positive behaviors or feelings we wish to adopt. While the specific messages will vary depending on the goals, successful ones usually have the following things in common:

• They are phrased in the first person.
  "I am getting stronger every day…" not "You are getting stronger…" even if the affirmations are pre-recorded or being read aloud by someone else.
• They are phrased in a manner that concentrates on the positive aspects of change not the consequences of ignoring the issue.
  "I feel better now that I am losing weight" is good, "No-one will want me if I'm fat" is not.
• They are spoken in the present-tense, not the future.
  The objective is to help re-enforce an emotion, feeling, or attitude immediately while listening, not develop a plan of action for later.
• They are short and specific.
  Think of them as 'sound bites' for the brain to easily digest and remember to help you keep focused on your goals.

Provided your brain doesn't want to reject the idea (a big part of the reason it's important to focus on the positive), repeated enough times your subconscious will indeed start to believe that which it hears enough times.

Affirmations can be used alone as a tool for change; used audibly or even just repeated as thoughts during quiet meditation. They can also be combined with other techniques such as hypnotherapy, binaural beats, relaxing background music and other audio as part of an overall self-help program, and can be quite an effective tool when used properly.