Meditation question

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?