Simplified, the Law of Attraction states that your thoughts become reality. In essence, you attract to you the things you think about most. Sounds pretty simple right? The problem is, most people are constantly thinking negative thoughts, usually subconsciously. So, you may be attracting negativity into your life and not even be aware of it!
In order to properly utilize the Law of Attraction, you need to change your thought patterns. Sounds easier said than done, right? Wrong. Somewhere along the line, you may have developed a negative thought pattern, whether it is due to your upbringing, family circumstances, whatever it is that happened that made you feel out of control and helpless. Recognizing and bringing to your conscious mind what it is that happened to make you feel out of control and powerless is the first key to successful manifesting. Realize that you now have control over your life, and that you can take steps to gain control over your thought process as well.
Start with something simple. Don't go for the big things all at once. It takes practice! Focus your mind on one thing you would like to change about your life. Make this be your mantra, let it be the first thing you think about in the morning and the last thing you think about before going to bed. Most importantly, make sure you make this a positive phrase! Instead of focusing on losing weight, for example, just focus on how good you would feel being thin or buying the size clothes you'd like to be able to fit into. Your subconscious mind is attracted to positive thoughts. If you think negatively, you will also be drawing this negativity into your life. If you keep thinking, "If only I wasn't so fat!", you are focusing on "fat" and therefore bringing this into your consciousness.
It may sound confusing, and changing your thought process can be challenging, at first. Practice really does make perfect. Set reasonable goals for yourself, and save the biggies for when you get really good at it. Just remember - replace your negative thoughts with positive ones, and be consistent doing this! Mentally stop yourself, picture a big red stop sign in your head, whenever you find yourself thinking something negative. Literally do this, and you will be one step closer to living your dream life. Remember - it's being positive and consistent that brings about results. Like attracts like, so by being positive, you are only attracting more positive things to you. Good luck!