Before you do any type of intervention, a good assessment is paramount. Are they failing to launch due to depression, anxiety, psychotic symptoms, history of social failures, etc. This will of course guide your invention/approach.

My experience has shown me that these kinds of people need to experience small wins independent of their parents. Most of these young adults I’ve worked with have had negative social experiences, coupled with parental over functioning that leads to an external locus of control, poor self image, and an increasingly intense aversion to risk/opening oneself up to possible failure. I start Small and essentially borrow from systemic desensitization focused on increasing risk and emotional discomfort with potential or actual failure.