I know some of you may still have minor hallucinations even after medication. I've been working on developing methods to control them to some degree. I've found the key is in how the mind interprets sensory information. The placebo effect proves that beliefs can influence whether we feel better regardless of the effectiveness of medication. There is also some study into eye witness testimony that suggests witnesses interpret information as a mix of what truly happened and preconceived beliefs. My hypothesis was that things that are entirely mental creations should be heavily influenced by belief. I myself am schizophrenic and have used this to influence images I see across my vision regardless of medication. I found that positive beliefs about what would appear next led to less disturbing images and more pleasant ones. This may help explain why religion has a positive effect on mental illness. There is still much to discover on this matter and I'll keep you updated if I find the time.
Disclaimer - This is not a substitute for medication but may be helpful to those who suffer from negative hallucinations regardless of medication.
Any other tips and tricks regarding this subject are welcome.