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).
DIY has potential, but it depends on how many people are working on DIY projects. For some reason, my brain went to DIY HRT when you said that, btw. I guess I'm that trans-brained...
I've thought that c/writing might be cool to focus on, but similarly to DIY, it depends on people actually working on projects involving writing.
So, at least for the latter two, their existence can be broadcasted to more users via c/main or c/CTH, and Howdy could have forced participation (I've seen users introduce themselves on c/chat). I thought about maybe having it be a way for users to introduce others to certain topics or interests, but it's a deviation from the comm's original purpose, and it might overlap with other comms like games or literature.
