An ~art sub could be nice for showcasing your work and receiving tips. There is a similar concept here: https://xmrmemes.com/ (but it's for memes, not artwork, and it uses Monero) With a ~marketplace sub you could sell commissions and finished artwork.

For cryptographic ownership, it may be possible to e.g. post an IPFS URL in Bitcoin's OP return. Not sure if there is already any NFT implementation for Lightning.

For other creative work, a value-for-value streaming platform for music and TV shows may be nice. Possibly also a value-for-value ebook app.