Find time where you can step into a room and close the door. If you have children, make sure someone else is watching them, or if they are old enough make sure they know to not disturb you (except in an emergency). Set aside 15-30 minutes.
Sit however you are comfortable. Some people like sitting on a bench with their legs underneath while others prefer sitting on a pillow while their legs are crossed. Rest your hands on your knees.
Playing music will drown out distracting sounds. Once you are comfortable, close your eyes and intentionally relax your muscles: first in your face, then through your entire body.
Once you are relaxed, focus on your breathing. This helps keep your mind in the present moment. As you breathe in, you can say in your mind, "I am breathing in." As you breathe out, say, "I am breathing out." Your mind will wander - do not fight your thoughts. Simply acknowledge them and return to focusing on your breathing.
Continue to do this until your allotted time is up. As your practice becomes more frequent, you will be able to focus better for longer periods of time.