A stress free life is practically impossible. Stress is the response to the challenges. Challenges are caused by the goals. Achievement of goals are called success. In short no stress = no success. So stress is a good thing but most of the stress in our life are unnecessary. You can easily eliminate this unnecessary stress by applying simple (or not so simple)baby steps. Off course it cannot be done overnight as I have been doing it for a while and I still have a lot to do.
You have often seen the articles of how to relax after a stress full day, and most of them are really quite useful. To further the quest, I made the goal to get the source and cut the stress before it even happens. (Yes. The same as X-Men. Days of future Past).
To nip the evil in the bud, I have devised a list, and by editing your life according to it you can eliminate most of (not all) of the stress in your life.
This may seem contradictory to add more task in your life when you already know you have too much to do. But if you want to add some new flavors of emotions. This is the thing! Helping others does not require a set pattern or formula. You may do it by giving ten minutes of your time to your colleague, participating in a charity or volunteering yourself or even making effort to compassionate with the people you meet. It would not only give you good feeling but also will lower your stress. But it would certainly not work if you try to control others or help in a rushed or frenetic way. Take it easy, try to feel the pleasure and value they are getting from you. Enjoy yourself as you are working to make the lives of others better.