Affirmations are a wonderful way to start rewiring the brain by thinking or speaking in a different way. They help to interrupt the unwanted habitual thinking that may be blocking you from further growth and harmony while at the same time introducing your desired result.
Now it is important to realize that affirmations are not an end in themselves, by that I mean it is unlikely that you will see the change you long for simply by repeating an affirmation hundreds of times. They offer the most affective results when we understand they are best used as a trigger.
For example, if Opening Heart Chakra blockage symptoms you are looking to change the way you deal with a particularly challenging coworker, you might pick an affirmation like~ There is an infinite supply of Love in my heart.