NFT Art, just like all arts, requires some basic marketing/promotional skills as well as a few specialized things because many people still don't know how to use opensea, have some ethereum, and what makes this art so valuable.
My recommendation is to post to communities that know what's NFT and so might pay for it and some of them:
- Bitcointalk (here), Reddit, and Quora: communities are ideal places for cryptocurrency lovers but look for all the other communities that don't have a problem with NFT.
- Twitter, Instagram, Discord, Medium: they are perfect but you need to get some interested followers.
- websites-newsletterSome sites allow you to advertise your Art token. try it out.
you need to be lucky to sell these tokens at a high value as I think a few tokens got a high value (less than 1% of the total)