This is more a discussion so feel free to give your opinions if you wish…
You have a constant stream of work to get through. You can either create tons of layers and layered processes “in case” you need to go back and change anything, or you can work fast and destructively. The work won’t be used in a magazine so revisits are unlikely and it is for your everyday client to have as a restored photo. Are you going to create three dozen, high resolution, multi-layered .psd files, layered up with all your restoration changes or just restore them?
With confidence in your processes and as a seasoned artist, it is perfectly possible to work through the images in a destructive way and save them out to single layer files. The thing with photo restoration is that you start with some pretty damaged photos and whatever you do it can only get better right? Provided you work in steps and don’t make any radical changes and have a feel for the end result, go for it.
If you are radically changing the background (something I don’t recommend) or airbrushing big time over skin tones (something I don’t recommend) then all you are doing is removing damage and patching up the cracks so there is no reason to keep loads of editable layers. If the image is ok to start with, exposure and colour are all good and there is some damage to fix. Just fix it!
On the flip-side you have a big image for the local bowling club, they are not sure of the reproduction size and or medium it is going to be printed on. They are not sure if they like it restored as is or improved and enhanced to give it life and punch. It is here you step back and create the layers you need to enable these decisions to be made without having to rework your image. The damage will have been restored but all the colour corrections and contrast layers are kept in place, ready for tweaks and adjustments when needed.
How would you do it? what is your opinion..?