Not every photo is perfect. I have 15 years of Photoshop and photo-retouching. I can borrow eyes or a face from one photo and replace it on another photo. I can add a sky where there was none. I can modify backgrounds and merge images. I do facial retouching and body shaping.
Standard retouching is done at the photographer's discretion. This may include: cleaning up pimples, whitening teeth, smoothing skin, scratches + bruises, reducing shadows under eyes, sun spots, splotchy faces, color correction/contrast and light background editing.
Additional retouching is available for a fee. This may include: eye, head or body swapping; changing color of clothing; editing logos from clothing; adding skies/sunrises/sunsets; changing backgrounds or combining images.