Understanding the structure of 64 squares
Firstly, memorizing colors of squares on the corner ( a1, a8, h1 and h8 ).
Secondly, memorizing colors of central squares ( d4, d5, e4 and e5 ).
Knowing that 8 x 8 squares consist of four 4 x 4 squares.
Knowing that 4 x 4 squares consist of four 2 x 2 squares.