Mindfulness (Sati in Pali) is a way of being aware or attending our experience that facilitates insight and wisdom. It is the technique and tool that we use in Vipassana meditation. The whole point of Vipassana meditation is to 'see clearly'. Let's take apart each component of the above formula.
Neutral
Neutrality when observing is the first key ingredient. We could also use words such as equanimous, pure, detached, uninvolved, unidentified, unbiased, non-preferential, and non-judgemental. Neutrality helps us see clearly because it allows us to be impartial. The more we prefer or involve ourselves in the observation, the less we will see the picture clearly. Just like a scientist who tries to stay impartial towards his experiment to be able to make an unbiased observation. If there is craving/aversion present that we are not seeing clearly, we are not neutral.
Observation
Observation is the seeing part of Mindfulness. We could also use words like consciousness, knowing, acknowledgment or awareness. Observation is being aware of what is happening. Just being neutral but dreaming about something else without knowing it is not observation. Observation is clearly aware of what is happening. Observation can be open, observing everything as it happens spontaneously or a specific observation of one sense such as just body sensations or just sounds or just thoughts. Clear observation is accurate and precise.
Mind & Body
Anything we experience is always Mind & Body. Body includes all 5 senses. Hearing, Seeing, Tasting, Smelling, Touching. Mind is everything else; imagination, thoughts, emotions, states of mind, reactions, intentions etc. We need to have a neutral observation of Mind & Body as it is happening without wanting to change or modify it. Through neutral observation, we see Mind & Body clearly, with wisdom and the right understanding. Understanding its nature. Understanding all Mind & Body begins and ends, all mind & body is uncontrollable, and clinging and grasping to mind & body leads to suffering.
at the Present Moment
The neutral observation of mind & body needs to be right now. Not thinking, imagining, or analyzing past or future. The more you are really just in the pure awareness of what is happening right now, the more past and future disappear. Time is just a concept/thought that's appearing in our awareness right now. When you are thinking about being mindful in future or past, that is not being mindful right now.
What is the right mindfulness?
The right Mindfulness will be energizing, enlivening, and freeing. When you are very in the neutral observation of mind& body at this moment it gives a sense of freedom. Freedom from anything that is happening or bothers you. When we have the right mindfulness we understand the nature of everything that's appearing. Understand that it is constantly beginning & ending, arising & passing. The right mindfulness is all about seeing reality and experiencing truth.
We can check if we are really being mindful. If something still bothers you or you feel a sense of struggle, there is something in your experience you are not seeing/accepting. If there is still past & future you are not in the right mindfulness. If there are some ideas in your mindfulness, ideas of what it should be or comparing it, you are not in the right mindfulness. If there is thinking/considering or analyzing you are not in the right mindfulness. Sometimes there is too much concentration power and we can block out or suppress parts of experience, which is also not the right mindfulness.
We will get it wrong over and over again but over time, more moments of right mindfulness start to happen. Don't worry, each time you get it wrong, you are learning. We build a better and better habit of right mindfulness which helps us instantly apply it when we need it.
What is the result of right mindfulness?
The right Mindfulness sees clearly. The right mindfulness separates and deconstructs our sensory experience. It distinguishes and can discern between the different components that make up the usually very tangled, complicated, and messy sense of reality. The deeper the mindfulness, the clearer the picture and the less room for delusion and ignorance there is. Ignorance gives rise to craving and aversion and the resulting suffering.
Below is an example of how mindfulness deepens as it's applied to feeling the breath.
0. No mindfulness. We are thinking and fully believing our thinking.
1. Conceptual mindfulness. Here we see our sensory experience through our words and concepts. The predominant part of the experience is the idea of what we are doing, for example, "I am breathing", "this is an inhale", and "this is a long/short breath".
2. Phenomenological mindfulness. We are mindful at the moment of contact of reality with our senses. We feel the sensations of air on our skin and inside our nostrils. We can observe the heat, cold, tingle, itch, etc.
3. Mindfulness of Change. Our mindfulness sees the components of phenomena and sensations. That they are constantly changing. The change of phenomena becomes predominant. We can still access the knowledge of what kind of phenomena they are e.g. hot or cold but we just see the arising and passing.
4. Mindfulness of Emptiness. The predominant experience becomes the emptiness or ground from which all sensations arise and pass away. We could also call this awareness.
The different levels are not discrete but all overlap and shade into each other. You might be at level 2 in one moment and then back at 0 in the next. No level is better than any other and each level is useful for different things. For instance, level 0 is useful for thinking and writing this sentence. Level 1 is useful for examining how we think and our psychology. As you get more skilled you can switch between the various levels at will. Mindfulness can be applied to any experience. Our skill of mindfulness can be applied to thoughts, intentions, pain, emotions, and sensations.
In Conclusion
Developing the skill of Mindfulness helps us see our experience more clearly. We are able to see the truth of what we are experiencing in each moment. Most humans in this world only have access to the conceptual/thinking layer of the mind and are thus constantly living in ideas and abstractions of the present. It is in this layer that our ideas and expectations can create a lot of dissatisfaction and discomfort for us as the mind is constantly projecting into past/future, most of the time worried, anxious, disliking or craving something. Suffering comes from comparing and wanting experience to be different than it is.
As we develop the ability to use mindfulness when it is useful, we can choose how to relate to our experience. To stay with content and ideas if they are helpful, and not harmful but to also have the option to deconstruct and see through unhelpful or harmful illusions. As we see deeper and deeper, we develop wisdom and insight into our being and the way we experience the world, allowing us to live a better and more harmonious life.
Sources: Levels of Mindfulness adapted from Michael Taft's model "Reversing the Stack". What is Mindfulness? by Shinzen Young. Great long PDF about Mindfulness.