Bad things are not alone in being superstitiously grouped into threes; design aesthetic holds that three is a good number of objects to visually take in at a time, popular sayings contain three parts ("Reduce, reuse, recycle!") and, I would suggest, good things also arrive in groups of three.
I was first exposed to literature on the topic of positive thinking about 5 years ago, and I have found it to be incredibly challenging to rearrange my line of thinking and become more optimistic in the hopes that my thoughts will be reciprocated by the universe.
My latest meditations have been over this particular threesome: Mind, Body, and Spirit. All must be on board in order for growth and movement to occur. What does this mean to me, specifically? Think it. Act it. Feel it!
An example: I'm flying to Chicago next month, and I've found myself growing increasingly anxious about the flight itself as the date approaches. I know that a large percentage of the population suffers from a fear of flying, but I also know I must get this fear under control in order to look forward to this trip. To apply the above process to this situation means:
Think it: I know that flying is safer than driving, and I drive all the time. In addition, I know rationally that I have flown many times in the past with no incident.
Act it: I must be in control of my body and relax my muscles and breathing on the day of my flight.
Feel it: Go to my mind's happy place after I board the plane. Master my emotions and remain focused on the goal and the fact that after I land in Chicago, happy times await.
I challenge you to think of areas in your life that can be improved by setting goals and then reflecting on the alignment of your mind, body, and spirit.