There's no "magic button" for photographs, honestly. Study what makes magazine cover shots look good. Ten to one it's stuff that happened BEFORE the photographer snapped the shutter: things like hair, makeup, location, and lighting, lighting, lighting (as well as a photographer with good glass and a good camera body). The rest is just adjustments to the image as a whole and cleanup (or for fashion stuff, probably airbrushing, which takes some artistic talent and practice).
Garbage in, garbage out. Quality in, quality out. Post-processing is for tweaking an already good photograph. You can only polish a turd so much. 🙂