Sit in your preferred posture (hand over hand is recommended) and close your eyes. The idea is to remove external stimuli or at least minimize it.
Have strong determination. Set an intention to not "itch the itch" or get up.
Witness the sensation of your nose and upper lip (pure object of your focus) as you breathe in & out.
Breathe in, notice object. Breathe out, notice object.
Notice the sensations arising, passing and changing. Be Neutral.
Concentration Mature?
Attain a pure minute or two of only the object within a 30-60minute sit. A longer duration of pure concentration is most helpful.
Proceed to