I am not a pro, nor do I intend to ever become one, however I do have some stuff I've managed to do over the years, I'm thinking of sharing some of it here.
so here's what I consider my best work of photo manipulation.

I pulled the original image off a webcam looking over my home city, and did some lighting changes, as well as changed the sky and stuff to look like it's literally on another world.
this one I did a bit later, inspired by the Halo series I wanted to try one where it's based on a ringworld.

I'll see about pulling some of my design work later since most of that is IRL drawn and not scanned in unless I do a 3D model mock up from it for fitting and design purposes like cases and such to be 3D printed.