This is a really simple question of preference, but when tagging:

For communities, are you more partial to !community or /c/community?

For usernames, do you like @user or /u/user more?

For me, I prefer the former (! and @) because it feels quicker to write them that way and it helps me create mental separation between the Beehaw/Lemmy way vs. the Reddit way. Also, when linking, I like the more instance-agnostic link styles [!community](/c/community@instance.com) or [@user](/u/user@instance.com), even though it takes a bit of effort to write.