Maintaining presence once it arrives is one thing but for me the frequency of being present is a greater problem. I almost never remember to be present.
In the beginning, the trick to being present is to remember to invoke presence. Of course we forget to do so. We are asleep. We continually forget those things that are not habitual or do not immediately serve our interests. And sometimes when we do remember to invoke, the momentum of sleep in our biological machine is so strong that presence does not enter us. We continue to be identified.
Presence becomes more possible when we have observed ourselves enough to recognize our sleep patterns. Observing these patterns in real time, as they unfold, reminds me to invoke presence. Then sleep in not the enemy but rather the practical means for reminding me to wake up.
Another valuable step is to begin to recognize when you are called to be present, rather than relying on the fact that some part of you may occasionally want to be present for some entirely unreliable reason or other. There are situations that call me to be present. If I am not present for them, I feel uncomfortable and I may have a sensation of remorse afterward when I recall my engagement in them. Group prayer is an obvious one. Meeting with a friend who is in distress is another. In time, you may succeed in establishing obligations that require you to be present.
What do you mean by the momentum of sleep?
I can remember to invoke presence. However, my body sensations may still be moving along a habitual path. I may be hungry or angry or pressed for time. The sensations that accompany my state continue despite my invocation and therefore presence does not enter. My identifications continue.
To be present in the present is to enable a temporary combination of body, mind and presence. To be more than fleeting, the body and mind must be accepting of presence, or at least not antagonistic. The secret to invocation of presence is to clear the sensation-palette and relax the body and the mind so that presence can descend into a relationship with them.
Let us suppose that you successfully invoke presence. Now presence has an opportunity to engage fully. This is what I call the three occupations. Allow presence to fully occupy the body. This means sensing where there are habitual tensions that typically carry you into sleep and releasing them.
Next, allow presence to occupy the mind. This means releasing your hold on thought and allowing the mind to become formless. In our ordinary states, we hold onto some thoughts and push others away. This effort actually gives a kind of limiting shape to the mind which can be sensed. It also corresponds with a way of tensing the muscles of the head, especially the jaw, which can also be released. When the mind becomes formless, it is spacious and open to the experience of presence and it then operates differently.
Finally, allow presence to occupy the heart. If body and mind are aligned with presence, presence itself can accomplish the occupation of the heart, which awakens. Now there is nothing to interrupt the flow of presence. This is the momentum of presence.