(talking about microblog fedi here, Lemmy/threadiverse is it’s own thing)
don’t do hashtags. hashtags (especially common ones like #memes) are overrun by repost bots and low quality garbage.
the trick is to be on a small-to-medium instance you vibe with (1k active users seems to be the sweet spot. anything larger than 2k I’d avoid. do NOT join any flagship instances like mastodon.social), follow fun people from your local timeline, and see who they boost. and follow up the boost chain until your timeline is sufficiently fun.