With chastity as your foundation, simply practice daily to improve your visualization skills, and complement this with mantras that have the I (eee) sound. In this way, gradually, the skill will improve and the chakra will work accordingly. A very effective way to do this is to practice retrospection meditation every night.
“Nothing is easier than self-deceit. For what each man wishes, that he also believes.” —Demosthenes
"Do not worry; cultivate the habit of being happy." —Samael Aun Weor