I Could Retouch using Photoshop or the Old way... My first retouching job started out with my boss asking me if I knew how to retouch (I didn't even know what it was). I responded with a confident YES. They asked me to go get what I need. What I needed was a book on retouching, I spent 3 days reading on it , on the 7th day I was ready... Now I could retouch with the best of them. I have retouched images that would make it all the way to 1 sheets, billboards and theatrical displays.
(See before photo) since this was St. Tropez she's supposed to be elegant fully jeweled and tan... I added the earrings, the jewels and the blouse, per the director. The hard part of airbrush retouching is getting the paint to thick, on this particular job the client had asked for revisions after revisions, with photoshop this will never be a problem..
Before airbrush retouching you have to plan ahead, way ahead. First you have to have a good image developer. Then you need to decide how you want to approach this job, using dyes and bleach, or a combination of airbrush and dyes.