If truth is relative to what you believe, then happiness is directly correlated to what you pursue.
Everyone is looking for ways to live a happy life, but in reality, the search begins with you. Happiness isn't "found," it's achieved.
We start here.
1. Stay true to yourself
So much unhappiness stems from making decisions that go against what you know in your heart, your instinct, is right. Deep down, you don't want to do it, but you do it anyway. You listen to your head. You try to convince yourself that the increase is worth it, or that the risk is too great, or that it's better to stay put, to keep your head down.
Staying true to yourself is challenging, yes. But effectively suppressing your true self is even more difficult.
2. Do what you love, not what you are told to love.
Spending time (especially a lot of time) doing what you love takes work. Hard work. And the truth is, most people give up. They get a job to pay the bills and do what they love "on the side." Eventually, they lose motivation, fall into the comfort of routine, and give up what they once enjoyed most. And for years, then, they look back with regret, almost basking in the declaration, "I wish I could..."
It may take you a while to realize it, but at some point, you will. You will feel an immense sense of loss for not having stayed true to the thing that once brought you true joy. Even if you never make it your career. Even if you only do it for yourself, do it anyway. The fact that "doing something for yourself" is considered a waste of time and energy is a testament enough to our achievement-based society.
3. Create the environment that suits you
If you're an extrovert, don't allow yourself to do a job that suppresses that part of you. If you're an introvert, don't try to contort yourself into an extroverted company culture. Your own happiness is a reflection of your daily life, the things you do, and more importantly, how you do them.
Create your own environment. Put yourself in a place that will help you grow, not suppress your growth. Surround yourself with people who understand you, or at least make the effort to understand you. There are always options. Don't settle for a place that doesn't nourish your heart.
4. Choose your friends wisely
You are a reflection of the five people you spend the most time with—choose them wisely. If they complain a lot, you'll inevitably complain a lot. If they're lazy, you'll become lazy. If they're not actively improving, you won't actively improve, unless you leave the situation and find other people who reflect that part of you.
It is very difficult to stay in a state of happiness when you are surrounded by negativity.