Howdy might be tough to get more activity on, unless it's purpose expands or it becomes a rule to post there upon making an account (which people should do anyway, it's fun).
One idea I had is to make it a space for “introductions and updates” basically a place to introduce yourself OR toot your own horn and brag about something cool you did or whatever. A space to talk about yourself.
For some reason, my brain went to DIY HRT when you said that, btw.
Why not encourage DIY HRT posts? Would be perfect for talking about recipes and such. If they try to restrict HRT, would be cool to lay (more of) the ground work for underground networks that make the stuff.
/c/creepy also has a ton of potential in my opinion. Could expand to cover horror in various media as well as stuff like true crime, occult, paranormal, etc.
LOVE this energy