A tech illiterate friend of mine just "hired" me to spread and promote her artwork through the internet, but frankly I'm just as lost as her.

She already has a huge catalog of both traditional and digital paintings (she works as illustrator) but never posted it anywhere other than something on instagram.

I figured making a Twitter, ArtStation and Deviantart account would be a good place to start, but how do you actually get your work out there?
I know twitter is all about hashtags and deviantart has groups for exposure, but my knowledge basically ends there. Any other platforms/methods?