Sometimes Hatha Yogis or different yogis give you meditation and you sit down and imagine your head center or heart center or throat center to make them unfold. There is nothing worse than that because you are forcing something for which it is not ready.
The best way to open the higher centers is to develop virtues through creative imagination and visualization and try to actualize these virtues in your life. The degree to which these virtues are actualized in your life, to that degree your higher centers become active. Higher centers unfold when their energies, in the form of virtues, manifest in the life and relationships of the person.
Imagination & Visualization, p.135