Basics - The Laws of Attraction state that what ever you keep your attention on; you will draw to yourself.
Ex: If you dwell on a bad relationship full of resentment; then that is how YOU will feell; not the person you resent but You.
You attract to yourself whatever it is that you keep thinking about ALL DAY LONG.
It can be simple or it can be complex - it matters not - the results are the same.
In a simple way to practice - wake up and think to yourself - "I am going to have a really BAD day, in fact, one of the worst days ever!" Keep that thought with you...DWELL on it.
See how it goes....
Then tell me it doesn't work!