#asknostr - usage of #hashtags - is there a recommended way (community building)?

#asknostr - I'm wondering about the usage of #hashtags .. is there a recommended way to do it?

I think #hashtags can help a great deal in building communities, which is - I assume - something that everyone on nostr wants.

And I think it's worth discussing how people can be constructive about using hashtags so that the network becomes a valuable collection of content that can be browsed/discovered without much friction .. instead of a giant pool of mostly unsorted content that randomly passes through everyone's feeds.

So the question is: what heuristics/rules/systems do many people apply, when using hashtags, in order to make them useful?

One obvious (to me) rule would be:
1. Be hesitant rather than liberal when using hashtags .. to not #spam them and thus make them useless.

What do others think?