At the end of each day, congratulate yourself for accomplishing whatever you believed was your most successful event of the day, even if it is something as small as getting an email from someone. The key is to never allow your day to end with a negative thought.
I use this technique myself and have shared it with thousands of others over the years. Those who do put it into practice often come back to me later on saying how much of a positive impact it had on them.
Many times, the most successful tips are the simplest and this one doesn’t require any great skill. It just requires you to find the positive in everything you do. Even on bad days, there is always something to be grateful for. Don’t waste time lamenting about the bad stuff. Focus on the positive and use it to influence your outlook.