When I meditate after maybe 30 minutes I notice a shift and the meditation feels like suddenly not as much or no effort is required. It’s a nice calm feeling. Thoughts are almost non existent. Usually I just continue to sit and note whatever comes to my attention. Sometimes it’s boredom so I also note that. Is there something else I need to do to deepen the meditation further or should I just keep noticing and letting go?
Just sharing as I am also just a practitioner trying to improve my meditation.
I think the mindfulness quality is very important in our meditation practice. If you notice a shift to more stillness after 30 minutes, perhaps you can try to note the qualities/conditions of the mind that allow this stillness to settle in. Then try to get the mind into this state by actively giving rise to these qualities/conditions as early as possible in the meditation (if possible right from the start). Consider it an improvement if you can shift your mind into a state of stillness sooner in subsequent meditation session.
Mindfulness acts like an observer, it is an automatic quality that remembers our experience. We can use it to play back our meditation session. A mental nudge I rely on is to ask a question, “Is there something else that I can improve on in my meditation?”. We can do this before (to prepare the mind to settle down) and after the meditation (to review the areas for improvement). During the meditation, just give it our all to execute our plan of action.
I think this active process of reviewing is something that is also mentioned in the suttas e.g. MN111.
Known to him they arose, known to him they became established, known to him they subsided. He discerned, ‘So this is how these qualities, not having been, come into play. Having been, they vanish.’ He remained unattracted & unrepelled with regard to those qualities, independent, detached, released, dissociated, with unrestricted awareness. He discerned that ‘There is a further escape,’ and pursuing it, he confirmed that ‘There is.’
Letting go requires us to know what qualities in the mind to abandon, merely abandoning without discerning what is good or bad would not, I think, be helpful in our meditation. We should let go of those qualities that give rise to stress and hinders the mind from entering into deeper concentration but keep those qualities that allows the mind to settle into deep concentration quickly. With Metta.
Just to build on Dhamma Dhatu's answer - what he's describing is absolutely correct. Practically speaking, however, such simplicity is an advanced technique which you might not be able to implement fully until you've been practicing for a few years. For now, certainly continue to let go. But I'd be especially mindful of instability in both body and mind. For example, you shouldn't move at all for your entire session. Likewise, you are going to find that your mind is pulled all over the place. It may be helpful to anchor your attention on an object be it the breath or what have you. You will still be letting go, but think of it in terms of letting go of anything that isn't your chosen object. You aren't so much "concentrating" as you are keeping your mind in one place. Mental stability, not laser point focus, is what you're after.
Another thing I'd advise is that after 20 or so minutes into your sit, really let your awareness fill your entire body. This will probably result in feelings of tension or other strange sensations such as your body twisting, becoming larger, etc. Just let those things happen. Don't shift positions or try to fight them. Over time, they will start to dissolve on their own. You can also speed up the process a bit by relaxing into them or letting them wash over you. Whatever you do, don't try to fight these sensations.
Lastly, if you really want to make progress, increase your sitting time. 30 minutes is just about how long it takes to "warm up" with samatha practice. Your best "gains" come after about an hour and start to peak right about the 90 minute mark.