find something to post on a regular basis. e.g. on [email protected] I post a weekly announcement about the upcoming Monsterdon movie viewing (with links and background info); LaurenceWolse posts 2-3 movie overviews a week, and there we have the basis for a moderately active sub.
find another couple of people to help you out by posting regularly
keep posting on this community’s weekly thread and getting advice/inspiration from other posters here
I guess to revive a community: