What: Adopting a fixed spacing scale (multiples of 4 or 8) for all distances in a design.
Why: A single scale makes spacing harmonious and calms the design; random spacing looks disjointed.
How: Make every margin and gap a multiple of a base unit (4, 8, 16, 24…), using no values between.
Common mistake: Random spacings (7, 13, 19) that look unintentional.
Exercise: Retune a design so all its spacings become multiples of 8.