back in the olde days a magic bullet was made by melting down religious icons. the silver was used to kill werewolves. in photographic terms, a magic bullet is a cure all, a combination of materials ( paper, chemistry and film, and technique ) used to make perfect photographs. its almost like something a photographer can do to make their photographs better, without trying. for a long time magic bullets were sold by kodak tri x and d-76, kodabromide and dektol come to mind. these days a magic bullet might be a vintage lens, large format camera using film or a digital camera. if you boil it down to its essence, a magic bullet is what makes the person comfortable behind the camera, the darkroom, infront of their computer.
merriam webster describes conventional as something that has been around a long time ( paraphrasing ), something that is considered “traditional”
http://www.merriam-webster.com/dictionary/conventional/
i guess all photography is conventional … seeing no matter what is done with camera, someone has probably done it before, i suppose it might be nearly impossible “unconventional” …. unless one weaves modern technology into and creates hybrid images.