To ingest both ecstasy and psychedelic mushrooms. Candy flipping is mixing LSD and ecstasy. Although some might think hippie flipping is combining LSD and mushrooms, this is incorrect. There might be some areas where people define it this way, but the VAST majority of people define hippie flipping as combining ecstasy and mushrooms. It's drug slang, so majority rules. Google it and you will find this to be 100% true. Trust Erowid, Shroomery, BlueLight, Mycotopia, etc over one person on Urban Dictionary.
The practice of mixing psilocybin ("magic mushrooms") with MDMA or ecstasy. This often creates an amplified effect even if the user only took a small amount of each drug.
"Dude, I was rolling so hard on that E last night..."
"Yeah, but not as hard as Susie; she was hippieflipping on ecstasy and shrooms at the same time!"