Which mindfulness technique should I choose?

Namo Buddhaya. I am a beginner.I want to dedicate rest of my life developing mindfulness.I know there are four ways of attending mindfulness. I understand all the four ways. However I am not sure how to undertake all the four ways of attending mindfulness. Is there any progressive way of attending different mindfulness techniques? Should I choose different mindfulness technique at different times ? Which mindfulness technique would be useful for me ?