There was a time not too long ago when I complained so much my younger brother called me out. I had started to believe all the untrue stories my mind had created over the years. I was 26, and living a life that did not make me happy.

I went searching for answers -- and turned it around. I learned powerful hacks used by extremely successful people, including Will Smith, Oprah, Jim Carrey and Muhammad Ali.

About a year into the process, I dreamed of starting a tech company. Today, I'm grateful to be living that dream. It never would have become a reality with my old mindset.

I learned many things while changing my attitude and mindset. But of all the things I tried, these two habits still stand out the most. They seem simple, but they're powerful - and they work.

1. The power of visualization

Actor Jim Carrey once wrote himself a check for $10 million dollars for "acting services rendered," and dated it on Thanksgiving, three years in the future. He was broke at the time, trying to make it as an actor. Three days before the deadline, he signed a contract worth $10 million for his role in "Dumb and Dumber."

Writing that check is an example of the power of visualization. It's best summed up by Bob Proctor, who wrote in You Were Born Rich, "If you can see it in your mind, you can hold it in your hand."

You can tap into this power very quickly with a vision board. It's a fun and effective hack to kickstart success in your own life. You pin photos or other items on a cork board that represent your goals. You can add anything you desire. They can be things you want to own, a job you want to have, a higher salary, or places you want to travel.

When looking at your vision board, focus on the feeling you'll have when you achieve your goal. Feel as if you already have it. That's the key. I'm amazed how many things have come true in my life after visualizing them, and tapping into the feeling of already having them.

It's important to remember that this is your board - not the board you think you should have. Tap into your desires. Don't judge them. Don't limit yourself.

2. The gratitude journal

What's funny is that when my brother pointed out how much I was complaining, I wasn't even grumbling about my personal or professional life. I was complaining about my favorite baseball team. But he had noticed the bad habit -- and challenged me to stop.

I went searching for answers, and I found Shawn Achor's famous TED talk on happiness. I followed his advice and started keeping a gratitude journal. It quickly changed my mindset.

Every day, I make three entries into a notebook. When I have a victory at work, I write that down. If I have a bad day, I write down something more basic, such as "I'm healthy," "I have great friends," or "I can worry about my startup because I don't have to worry about food or shelter."

I also write down intangible victories, like "I was patient today with Chris and didn't interrupt him."

As a result, I quickly stopped complaining, and started seeing all the good in my life. It made it possible for me to start my company because I chose to see possibilities instead of giving in to doubts. I realized just how much there is to be grateful.

These hacks work.

They seem simple, but don't underestimate the power of these tools. They are the reason I have so much to be grateful for. They are the reason I have accomplished virtually everything on my vision board and have transformed my life. They are used by some of the most successful people in the world. If it's works for them, it'll work for you.