Namo Buddhaya. I am a beginner.I want to dedicate rest of my life developing mindfulness.I know there are four ways of attending mindfulness. I understand all the four ways. However I am not sure how to undertake all the four ways of attending mindfulness. Is there any progressive way of attending different mindfulness techniques? Should I choose different mindfulness technique at different times ? Which mindfulness technique would be useful for me ?
You have to do all four. Cannot skip anything.
- When you are walking or sitting and focusing on the belly or moving any body part, it's the mindfulness of the body - Kayanupassana.
- When you are feeling pleasure/pain, it's mindfulness of the feelings - Vedanaupassana
- When you are thinking past/present/future thoughts, it's mindfulness of the thoughts - Cittanupassana
- When you like, dislike, fear, doubt etc. or be aware of seeing, hearing, smelling, tasting, touching, it's Dhammanupassana
Whether you know these by correct category is not important. What's important is if you note each and everything without skipping.
The way I was taught, is that mindfulness is not practiced in-and-of-itself; instead it comes from a critical attitude to ourselves, which in turns comes from a certain goal that we set for ourselves, a certain standard of behavior.
For beginners, this goal or standard is the attitude of egolessness and non-attachment. We watch our reactions (thoughts, emotions) for signs of attachments and egoistic attitudes, and learn to overcome those, learn to be selfless. As we watch ourselves with that goal in mind, we develop a habit of awareness or mindfulness - of our mind and emotions.
For mature practitioners who have mostly mastered selflessness, the next goal is generation of positive, uplifted, powerful state of being. To achieve that, we watch our posture, gait, manners, our inner sense of comfort or discomfort, and we learn to walk in peace and gracefulness. As we work on that goal of peace and gracefulness, we develop mindfulness of our body, and a deeper level of mindfulness of mind.
Right mindfulness is NOT going around with eyes wide open, trying to do everything painstakingly deliberately. Most of our skills - from walking, to talking, to driving - are developed from scratch to the point where they become automatic. Being deliberate is only useful when you are trying to change a (bad) habit, but once you have established a good habit, it works better (faster, more smoothly) when your slow discursive thinking does not interfere. Ask any sport professional or musician or dancer about developing right instincts and right automatic responses.
So in Buddhism, mindfulness serves a goal. First we practice mindfulness of our (selfish) goals, attachments and reactions - in order to overcome them and develop the new habit: operating out of wisdom and compassion. And then we practice mindfulness of our psychosomatic state - in order to overcome inner conflict & suffering, and develop the new habit - living in peace and harmony.
Once we have achieved our two objectives, hard mindfulness is no longer necessary. In fact, at that point it would interfere with spontaneity of suchness, which is the final phase of Liberation. So at some final point very very far down the path, you are supposed to let go of all sense of self-observation and self-control and immerse 100% into spontaneity. It's not that you stop being aware and mindful at that point. It is that mindfulness has achieved such a level of perfection that it becomes fully integrated with spontaneity and suchness. At that point you ARE mindfulness.
Andrei Volkov's answer is pretty good and thorough and clears confusion.
I would like to further add a quick reference/point to resource that might help with extending context atop of what was written for the sake of Mindfulness (Sati) as presented in Pali suttas:
A clear description of the aim of mindfulness with breath is given there also, along with why Satipattana Sutta often causes confusion regarding four foundations of mindfulness.