It's all very well using certain techniques to improve well-being - mindfulness is a good example. Sure it can feel good to practice mindfulness. What's the purpose of doing so? The linked article reminds us that doing things just to feel good isn't necessarily worth pursuing. Doing certain things just to feel good can cause more problems than we had to begin with. Anything can be done under the banner of 'so I can feel good' or 'so I feel better' or 'so I can be happy'. All sorts of personally destructive actions can be justified under these banners.
One question is, how well do these actions work in the long term? Do they really get you to where you want to be in life, doing the things you want to do?
With techniques like mindfulness, they become useful and 'work' when we use them for a particular purpose and when we stay responsive to the current environment. Mindfulness helps us get present so we can clarify what is important in that moment, in that situation, and then do something thats actually worthwhile and helps us in the long run. It's all to easy to become embroiled in thinking that leads us to become stuck - we think hard about something that happened or will happen without following through on useful actions.
Focussing on actions that work for you, in the long run, in response to your current environment/circumstances might just be the most useful thing you can do. Sure, there are 'techniques' that can help you along the way - it depends how you use them and when you put them into practice.