Started working less. It forced me to manage my time more efficiently with the result of being more productive and happy in the end.

The second best thing that helped me being happy is just doing what I like. Whenever I see an improvement, technical or business related, I start making a plan to improve it and start talking with co-workers/clients about this. This resulted in me having better relationships at work and just doing what I like instead of building (/programming) something someone else came up with. I really like to be in control of whatever I'm doing. Still in my early twenties and trying to figure things out.

Any advice?