Hello CharonMonolith.
I scan watercolors all the time.
I have an Epson V500 scanner.
For small works:
I scan at 48 bit color, 1440 dpi actual size.
Do adjustments in Photoshop:
-Retouch out dust & scratches
-Set "levels" (brightness & contrast)
-Save .PS file at this point.
-Reduce resolution to 720 dpi
-Reduce to 24 bit
-Save a copy in .tiff format, & make a test print
-Look at test print, go back to original 48 bit 1440 file, and adjust "saturation" & "levels" accordingly, and create a new 720 dpi 24 bit .tiff file. (Usually make a few variations, & see what looks best.)
-Print new test prints
-choose a final version, or go back and adjust again.
This is a bit simplified, but it's a good recipe for good quality results.
Good luck with your project.