There is no best way, as I see it. Leaving sticky posts on forums is, as you say, repetitive, and I simply overlook them now. They become background. Usually it takes me a couple of days to notice if one of them is fresh. Sorry, but that's me.
Posting to a general announcements forum? Hmmmm.... I only view forums that I 'subscribe' to, to minimize my looking and maximize my interests. I guess I would subscribe to one, and look in when there is a new post, but then again....
Ken's comment is right on. He makes a good point.
Coop