This is a good question. The reason i think it is a good question, is because it is practical and not merely philosophical - one can truly benefit from putting the answer into practice. It is also a good question, because it gives me a chance to clarify wrong conceptions regarding common and mistaken interpretations of the concept of "living in the now" (TMHO, of course).What does it really mean to "live in the present"?Basically, it is about right-awareness. In other words - proper attentiveness to what is going on right now. For example: noticing the flow of the breath, the touch of the air or the cloth on your skin, the expansion of the heart when you're excited or the hole in your upper stomach when you're depressed. It can be more or less subtle: the sounds you hear - all the spectrum and all the amplitudes - without judgement nor active preference, yet with as much discernment you can have, if one is practice and capable enough, it can be also be the flow of the mind-stream - those micro mental events that compose the thoughts, the perception itself and the self-grasping. It is about opening up to the original experience of reality - before the mind makes the stories, the subjective-interpretations, before it jumps to future plans, hopes, fears, remembrance and nostalgia. It is about peace of mind, about resting at that deep home in our heart. It is about acceptance, about compassionate abiding without feeling the need to be somewhere else mentally.When one learns how to do that, the more proficient and natural his abiding becomes, the less confused and troubled the mind becomes and clarity increases. As the clarity increases, so increased the wisdom of knowing one's own mind, one's true nature and the nature of the world around as well as others' hearts. Thus, one's actions - mental, verbal and physical actions - become wiser, "cleaner" and more inner peace is achieved as well as better results in general. How can it be practiced?There are many simple, classic, practices. For example, mindfulness of the natural breathing, walking meditation, shamatha with an object and more. In youtube, you can find instructions. One of the great teachers i know, who focus on the breathing technique and takes it to really amazing heights, is Tich Nat Hann (thich nhat hanh breathing). i'm sure you'll find lots of other resources as well. It is important to understand that it takes perseverance and effort, because the nature of our mind is to roam the past and the future and it normally takes time to teach it to rest in the now. Also, there are supporting and obstructing factors, where the main ones are conduct and kindness: unethical/harmful conduct makes the mind restless while the opposite is a foundation for restful, mind. The same is with kindness: harsh talk and behavior vs. kind and loving approach. As the great Teachers say, unconditioned compassion and love are the doors to the now...Thank you for the question.