Whether it's affirmations or visualization, as long as you believe deep inside that you can get things you want or become the person you wish to be.
But when your subconscious mind(the direct link between you and the universe) picks up any feelings of doubt, it will continue to attract the opposite of what you wanted.
The trick is to reprogram your subconscious mind while you sleep, this way those negative thoughts and doubts are not around.
Your subconscious mind gets the message and you will be shocked at how fast manifestations come to you effortlessly.
Here's a guide that will explain everything in more detail and how exactly to reprogram your subconscious mind:
http://subconciousmindzone.com/the-r...et-to-success/