I am a HUGE believer in the law of attraction. It's thought to be a "natural" law, meaning that it comes in nature and is already here, whether we recognize it or not. There are many variations on the same theme: we attract what we think about, power of positive thinking, like attracts like, etc. Here are the KEY concepts for always getting what you want -
Ask the Universe for it. Make your request. Send a picture of what you want to the Universe. The Universe will answer. See this thing as already yours. The more detailed your vision, the better.
Write down your wish. Start with "I am so happy and grateful now that..." and finish the sentence (or paragraph) telling the Universe what it is that you want. Every day until your wish comes true, close your eyes and imagine your desire as if it's happening right now and see your imagination turning clearer.
Feel it. Feel now the way you will after receiving your wish. You must act, speak, and think as if you are receiving it now. This is actually the most important, powerful step in using the Law of Attraction because this is where it starts working, and sometimes if you do this you don't feel like you need it anymore because you feel like you already have it! Therefore, the universe will manifest this thought and feeling and you will receive it.
Show Gratitude. The Universe has done a lot of things for us. Paying the Universe back with some gratitude will motivate the Universe to do even more things and will draw more things into your life. Showing gratitude will turbo boost the Universe to manifest your request faster.
Trust the Universe. Don't look for what you asked for; this is where people tend to mess up. If you have to keep an eye out for an event that manifests your wish, it's only telling the Universe you don't have it and you will attract...not having it. Be patient. Don't stress the "how" of things. Let the Universe do it for you. When you take the Universe's job of worrying about the "how," this says you're lacking faith and that you're telling the Universe what to do when the Universe has far greater knowledge and power.
My fav Law of Attraction books: The Law of Attraction by Esther & Jerry Hicks, Manifesting Change - It Couldn't Be Easier by Mike Dooley, The Science of Getting Rich by Wallace D. Wattles, The Magic by Rhonda Byrne