The law of attraction is based on the principle that if you focus on on something it will come into your life.
Which means you should always focus on the positives instead of the negatives.
"I look like I'm losing weight" instead of "I still look so fat"
"I hope I get something nice in the mail today" instead of "Probably more bills in the mailbox"
And most importantly:
"Today is going to be a great day" instead of "Today is probably going to suck like yesterday."