So besides shooting a lot of food photography I also shoot A LOT of knockout images for clients websites. Here is a recent shot I did for sugar in the raw. I believe it is being used both in their sell sheets to restaurants and to be used on their website. A lot of retouching but hopefully it doesn't really show.
Curious to know why you needed that much retouching, for such a simple image. Was the packaging in bad shape?
They sent me two boxes. 1 was basically crushed. This one the corners were pretty beat up and then when you opened the box itself you got a lot of rough edges. The printing on the box also was not perfect. This is going to be used in several applications and they wanted it to be as perfect as possible. Also, we used lots of double-sided tape to help flaps lay as flat as possible. I am still not happy with the two from flaps on the fold out part.
I've done a lot of this work and luckily had access to the printer's layout file (mechanical).
Each face of the box would be saved as a separate file and imported into PS as linked smart objects, then skewed to match the photo's perspective. Adjust the lighting of the 3 visible panels with a gradient and add just a bit of noise.
Finish by rounding the edges of the box by painting a thin white line with a soft brush on it's own layer and adjust opacity to blend, otherwise the edges look too sharp.