Im not sure how to say. Its the ones that I feel most apart of I guess. Like I post a comic I like to comicstrips at lemmy world and then I usually look over all the strips posted by others in the last day.
I try to pick the most popular one. Posting to all just reinforces the fragmentation and spams anyone reading all our subscribed to all of them.
Lemmy’s overlapping communities are a pain in the butt.
I try to prioritize the community on my instance. If there isn’t one, I post on the most active instance.
Flip a coin. Seeing duplicate posts on the home page is annoying.
I pick whichever tends to be more active, or more positive, or more general. I am also aware of how LW is poorly in sync with other instances and so I have been posting to LW more often as I am mostly here for social interaction.