Retrain your mind

Find a suitable environment.
It should be reasonably quiet and free from distractions.

Sit in a comfortable position.
Sit with your legs crossed or your feet on the ground. If you get drowsy, stand.

Relax your body.
Start from the top of your head, your forehead, eyes, cheeks, mouth, jaw, etc., down through your toes, then back up again.

Mentally repeat your task.
For instance, you can say, “for the next twenty minutes, I will focus on the breath so that I may develop superhuman concentration.”

Focus on your breath.

Keep track of the number of times you have caught your mind wandering.
When you find your mind wandering, simply redirect it back to the breath at the nostrils and score +1 point for noticing it.