I'm not sure how best to achieve it but what I personally do are:
- Train at night when everyone is in bed to avoid being interrupted. It's better these early in the morning but I'm not an early person.
- I play some meditation music that I enjoy when I train.
- I either close my eyes or look at a point on a wall and try to focus on my breathing and what I feel in my body (hot, cold, blood pumping etc...).
- Not getting bothered if I'm getting somehow distracted but if I do notice it then I just gently put my mind back into my breathe and inner feelings.
So a lot of discipline and patience I think