Where to start the body work? As a general rule, I usually start with the panel that opens, like the hood in this case (doors, decklid). The reason is, if everything is adjusted properly, this is the panel that should be flush, or just a little higher than the fender in this case (this keeps the panel edges thin). The shape of this hood, will dictate the shape of the top of the fender. You don't want to body work the top of the fender, then the hood, then have to go back and re do the fender. So get the hood straight, then make the fender match it.