In my opinion, as you said there shouldn't be any automated curation. Not automated at all, so not a trail as we can often see. Not a big account with a big upvote value followed by few other accounts automatically voting.

A way to do this without any automation should be a curation account, encouraging people to delegate some POB to it. Manually curating content and reblog it !!

Most of time curation account only curate and even sometimes make a post of the best content they saw, here rebloging some posts should also help to have more curators without having to create an automatic trail.