I think the general principles of the 'Law of Attraction' re positive thinking is a good trait to adopt as long as it is not taken to the extreme of wishful thinking, blind expectations, or self-fulfilling prophecy without one putting in any rational effort into what is expected.

On the other hand, hoping for random unexpected goodness without putting any rational efforts is also not an effective trait for life.

As the saying goes, 'if one failed to plan, one planned to fail'. If one plan positively without too much attachments (counting chickens) to the results, there will be spontaneous positive outcomes.