As you can see, I have a bad habit of taking over the dinning room table when retouching photographs: side light from the windows is good (my excuse anyway) which is a must.
As most of my work is on matte fibre papers (even my inkjet prints are matte papers mostly) I can use a number of different spotting mediums.
Spotone dyes are (were) the best IMHO but Marshalls are now the only archival liquid dye I know of. Two other methods can be used with good results: a range of artist quality pencils & the Edward Weston use of ink & gum arabic. For this I use Japanese ink stick and varying amounts of the gum arabic; depending on how glossy the paper surface is.
Ink jet prints will sometimes get the odd white or pale spot that went unnoticed on the screen (especially in high-key images) they can be retouched using the same methods used for fibre prints. Yes I know I could just reprint, but sometimes I won’t notice the fault for several days.
It could also be that I have developed a parsimonious reason; the cost of Ilford fibre paper is not cheap now, neither is good inkjet paper. If the retouching is done well enough, it will never be noticed when the print is behind glass.
Two things from the above: a tip from my wife (an artist who uses both watercolour & oils) is, look at the image upside down in a mirror. The other being, leave a print where you can see it on a daily basis: both remove the image from the minds eye, one then looks at it with a fresh mind-set.