The Law of Attraction can be understood by understanding that ‘like attracts like’. What this means is that whether we realize it or not, we are responsible for bringing both positive and negative influences into our lives. A key part of the Law of Attraction is understanding that where you place your focus can have an intense impact on what happens to you. If you spend your days wallowing in regrets about the past or fears of the future, you’ll likely see more negativity appearing, but if you look for the silver lining in every experience that you’ll soon start to see positivity surrounding you every day. Therefore, the Law of Attraction encourages you to see that you have the freedom to take control of how your futures develops, shaping it in the ways you choose.

When you learn how to use the many powerful and practical tools associated with the Law of Attraction, you can start living and thinking in a more optimistic way that is specifically designed to attract even more positive events and experiences. Whatever you’re longing for, whatever your dreams and goals, the Law of Attraction can teach you valuable lessons that will bring you closer to your most treasured ambitions.

Claims of it's effect

Health
A core claim by New Thought authors is that our thoughts directly influence our health, and that this is due to the law of attraction. They believe that worry, fear, stress or other negative thoughts make people sick, while positive thoughts of wellness or love can keep people healthy and even cure illnesses. This can be seen in scientific studies where the placebo effect takes place. Those who receive fake sugar pills tend to become healthier due to the mere fact that they think they are getting treatment when they aren't. Proponents also claim that an important part of maintaining health and of curing illness is to be able to visualize yourself as being healthy.

Financial
It is claimed that if someone consistently thinks prosperous thoughts then irrespective of their actual situation they will experience prosperity in the future because 'like attracts like'. Conversely if a person consistently thinks that they are poor then that will be their future experience. One example used by Lisa Nichols in the film The Secret is as follows: "Every time you look inside your mail expecting to see a bill, guess what? It'll be there. Each day you go out dreading the bill, you're never expecting anything great, you're thinking about debt, you're expecting debt. So debt must show up.....it showed up, because the law of attraction is always being obedient to your thoughts". Feeling happy and grateful for the money you already have, is claimed to be the fastest way to bring more money into your life.

Relationships
Law of attraction proponents claim that it affects our relationships because whatever we focus on we experience more of. So if an individual focuses on another person's good qualities then they experience more of those, where as if they focus on what they dislike about that person then those will be the characteristics of that person that they experience. They also claim that if you can visualize that a certain person is being nice to you, then you will be attracting experiences that match those thoughts.

Ambitions
It is claimed that when someone visualizes clearly and in detail what they want to achieve, and focuses upon that image, that they set in motion through the law of attraction a chain of events that eventually culminates in the materialization of that vision. Charles Haanel says in The Master Key System, "You must see the picture more and more complete, see the detail, and, as the details begin to unfold the ways and means for bringing it into manifestation will develop. One thing will lead to another. Thought will lead to action, action will develop methods, methods will develop friends, and friends will bring about circumstances, and, finally, the third step, or Materialization, will have been accomplished."

Source: Abraham Hicks, Wiki