Someone on reddit asked about feelings of bliss during meditation. This is approximately how I replied:
Experiencing bliss during meditation is easier than you might think. See this link:
Breathe in a relaxed way and notice the pleasant feeling of relaxation. Imagine you are relaxing on vacation and totally at ease in pleasant place with no worries or cares. Does that make you want to smile? That pleasant feeling is the first inkling of bliss. After that you just have to grow it by patiently meditating on the pleasant feeling of relaxation. Smile when you feel like it. When you smile, notice the additional pleasant sensations and emotions that are released. Notice the feeling around your lips. Continue like that. That's all. There is nothing unfamiliar about it or the stages leading to it. Just a pleasant relaxation which increases to happiness, love, connectedness, and equanimity.
This process creates a feedback loop in the brain. Attention to a pleasant sensation results in feeling pleasure because of it. And the attention to that pleasure results in feeling more pleasure because of that. It's like you are happy because you are happy, etc. etc. etc. That is the role of attention. It happens in meditation because people pay attention, but you just need the attention, meditation is only a vehicle. You can do it walking, lying down, whenever you are in a situation where you can relax and pay attention to your feelings.
But read the link. The section on equanimity tells you how, according to Buddhism, this can lead to the cessation of suffering. When you learn to produce this feedback loop, not just in meditation, but in daily life, then anytime you feel an unpleasant emotion, you just accept it, relax, and return to the blissful state. It's that simple, it just requires practice. The way you become non-attached to external things is by becoming non-attached to internal emotions because the way external things get to you is through your own emotions. When you are happy, you don't worry about yourself and you begin to see that self is an illusion that causes suffering and keeps us from seeing things as they really are. Bliss is your true nature. (The brain does not produce consciousness, it filters consciousness.) To realize your true nature, follow the bliss inward to its source.