Over the years I've read and tried most of the major self-help systems and I was also a member of a Yoga cult for about seven years. I'd treat them like benevolent lines of Cocaine. Good for a short term boost of enthusiams and energy maybe, but really bad in the long run if you get hooked on them.

Occasionally I'll read some inspirational quotes to manipulate the natural dopamine hits, but I don't waste a lot of time trying to use the "systems" to change my life.