I posit that you discover your already existing contentment rather than creating it. Take a look at the word again. The root is content. It means happy with what one has but also it means "stuff". If you will, stuff that already exists.
Sure you might "get" it atop a mountain after a satisfying hike, but I bet if you rolled back to the times that you felt truly content, you'd see that it was during some normal everyday moment, and it happened because you had the time to look around yourself and observe that the world was simply working the way it should.
You had some basic needs met (Maslow) and you were able to step back for a moment and simplify your needs further. Slowing down and being aware probably facilitated the moment of acute contentment.
It follows then that the more slow observational moments you can string together, the higher the likelihood of feeling/discovering contentment.
Slowing down, then is the good idea here.