Hey all. I'm an old school tech blogger and community builder, having been part of Spark-Online back in the late 90s, the Cluetrain Manifesto, and countless forums since then. I'm a ten year veteran on Reddit with a ton of internet points, and I blogged about my industry on my site ImTheirWebGuy.com for about five years. I've had a number of popular posts on Reddit, G+, and Facebook, and have had tens of millions of eyeballs across my posts. I suppose I'm a volunteer because @apm invited me, but hell, I never turn down a chance to talk about something. :D
I think the biggest tip I'd offer is "play to your strength". I personally like to write thoughtful miniblogs that chew on a topic and pose some questions to get the audience engaged. I also think of specific other users who might have insight I want to gather, and I tag them in the post.
However, that's definitely not everyone's style. Some folks are more about the one liner or a beautiful picture. If that's your thing, then go with that. However, make sure it's something that's actually yours. Some platforms are basically recycled meme dumps, but that doesn't seem to sell well here. If you're sharing something here, make it something you've created.