The key is to find a procedure that works for you in terms of jar size, fragrance loading, room size, burning time and stick to that procedure. From a technical point of view, the perceived fragrance in a space is strongly affected by ventilation or air changes and most importantly the diameter of the wax pool as fragrance evaporates from the wax pool. A 3" wax pool puts out more than twice the fragrance of a 2" wax pool.