I have found in my experience that I am happier like this:
When decisions are made regardless of their result, not taking them generates uncertainty and a void that lasts in the time of which one will always be punished. In addition, learning when you make the mistake is much bigger than when you always win.
Be coherent in what you say and what you do since you are what you say and if you can not do it, you are failing your thoughts and yourself.
Be humble as you will meet thousands of people who in their ignorance or experiences reject your points of view, some rightly others without it.
Know yourself and be yourself. There is no worse thing than hiding parts of one's personality because he thinks that people do not like or want to fit socially.
To help others, in the few cases in which I have helped someone there is no greater and more honest reward from someone who really needed help and you gave it to them, to feel that special "something" even if it is not tangible in the form of gratitude is very special. We are social beings, we will always be.
Never stop learning something new.
Know the importance of time since it is something you can not return.
Long ago I had a near death experience, I wish everyone had it, it allowed me to find and value the things that are really important. Think about this "If hypothetically your doctor and after serious exams told you that you have one day left". What would you do? You took advantage of your life, are you happy?
Do not think of happiness as a cause, think of it as a consequence, when you look back it is when you discover if you have been happy. Sometimes running looking for happiness actually causes frustration.
Do not compare yourself with someone, that is, if I want to be intelligent, I can not compare myself to Einstein. For me that's wrong. Rather, each day the best possible version of yourself, what skill do you want to develop? What skills would you like to have as a person? Do it, be the person you want to be.
Seek your spiritual balance. All religions have things in common in the background, but limiting themselves to what each one thinks does not go with me. I built my spiritual experience with what I learned from different religions and that brought me a little closer to my faith, that reinforced it. I believe in life after death and I try my best because I know that in my next life I will continue to evolve, that is my motive.
Beware of selfishness, I believe that we humans always expect something in return, we believe that love is to receive, we give a chocolate to our partner because we want to "love" us. I believe that true love is giving and you can not expect something in return; logically discern if that person truly deserves it.