Concentrate on Third Eye/ Pineal/ Ajna Chakra (situated in the area of Pineal gland).
Pineal chakra exist in area of pineal gland, center of two ears (Where spinal cord meets skull), its sansation goes in center between two eyebrows.
How to concentrate:
Chose your breathe spot in breathe canal at the highest point in between two ears it reach from where it goes down in your body.