And this is immediately by a bunch of people commenting that they still read their Livejournal friends list all the time, they just don't have the time to actually write anything sizeable there.
So, it feels to me that two things are useful here:
1) We can be a little more active here. So, next time you have a pithy sentence to share then post it here, rather than on Facebook*. In fact, if you're comfortable sharing your public posts over to Facebook/Twitter then set it up here so that you can use LJ to write your long-form posts and then people on FB/Twitter can read them here and either comment there or log in to LJ with their FB/Twitter id to leave a comment.
(*I know that LJ would helping themselves dramatically if they had an LJ app that worked at all well, or had been updated in the last 18 months. This stuff is _essential_ nowadays.)
2) We can huddle a little closer together for warmth. If people are posting less then it's probably a good idea for those of us who are still engaged here to add some people who are actively posting. So, if you've posted in the last week or two, and are happy to be added by new people, leave a comment here with a snippet about yourself.
Obviously, if you _haven't_ written anything in the last few weeks then there's not much point people adding you, because you won't be giving them much to work with. But dashing off to your LJ to write something awesome and _then_ leaving a comment here can't hurt :->
(Obviously, this also applies over on Dreamwidth. Except for the crossposting to FB bit, which they don't support.)
Original post on Dreamwidth - there are comments there.