Living in the moment without indulging in it I find it difficult to live in the moment or go with the flow as i am reminded of the sense doors and hence am guarded in the present to not to be totally involved in the moment and I miss the flow or to experience the moment as it is. I am trying to follow the zen and the middle path. How does one practice being in the present ?
"Living in the moment" isn't a practice, but a result. It's another word for the mindfulness or wakefulness "muscle" that develops as you do your practice. So if you don't feel it, don't worry about it. 

Follow the instructions for your particular practice, and you will feel your "muscle" for living in the present moment gradually strengthening in your daily life. For example, as time goes by, you'll notice that it is easier to be concentrated in everyday situations, or that you are more and more resilient in recovering from strong emotions.

It isn't really "you" living in the present moment, anyways. Your awareness is always living in the moment as it is. You don't need to correct your awareness. If you try to live in the present moment, then you'll merely be constantly trying to do two things at once

When you watch the sense doors, it's your non-present "self" that practices turning itself toward a true present phenomenon, and it does it over and over again. It's the only tool you have, so it's normal if you feel that doing this is not in harmony with the "true" present moment. But it is the right way to develop the skill of returning to your awareness more and more often, so that it becomes more and more automatic.