I have the full Phototshop package with Topaz and Nik filters - to give finishing features like vignettes, etc.
I've been using variations of PS since the 1990s when I was studying post-grad fine art photography. I use all the 'hand' tools and numerous layers and masks - i.e. no flat files.
It is important to
1. asess the image to see what needs doing
2. correct for damage - marks, dirt, etc. with various tools, using layers for differential treatment of various parts of the image
3. re-asses after the above corrections
4. final corrections.
5. finishing touches - e.g. tones, surfaces, vignettes, borders
This is just for black and white initial images. For colour I would use multiple colour masks and layers. I don't colour very often on here as it often takes 1-2 days or much longer to complete.
I might have missed some processes

Gadget
Add - there is nothing wrong with using new filters, etc. as long as they are used as part of one's armoury rather than a 'slap it through' approach. I try to evaluate many of the new apps. If we wrote off all new apps because they made things easier, it would be akin to the Luddites!
Sadly, many of the scans on here are far from ideal, so we're often attempting to produce pearls from the preverbial!. Scans should really use a non-lossy format* and at, at least 300 dpi.
*tiff, png, raw and psd for example.
add/ though jpg with no compression is next best as RC doesn't accept many of these formats
It's also important to use the right equipment - I use a large Mac and a Wacom tablet for art/photo work. At the moment I'm using a tiny laptop, which limits what I can see and do
