I have heard two ways off approaching mindfulness of breathing:
Breath in a inhale-pause-exhale-pause pattern, focusing on the sensations of the breath at the nostrils and the silences at the pauses between breaths.You would control your breath in this method.
Quiet your mind and just follow the sensations of your breath as it naturally arises.
Questions are
- Should you control your breathing if you want to reach the Jhanas?
- Which one is best if you want to attain the jhanas?