Soooo it seems from some of the threads that we as forum members might need a refresher course on this! (Granted, I don't know how many people even read this section, but I thought it might be a good attempt anyway.) Plus, some people have expressed confusion at what is and isn't considered unacceptable, so perhaps if we share what we do like to see we can all get a better idea of what we'd prefer not to see?
So what, to you as a forum-reader, are good guidelines for keeping posts civil and red-ink-free?
Here's my top 5 things I like to see for successful discussions:
1. No sarcasm. When in doubt, don't do it! Even if you mean well it might be misinterpreted, and if you're using it out of anger, you're not making things any better. Things like "Well I'm so happy your dog is perfect, but here in the real world..." etc. aren't terribly useful.
2. No discussing other people's individual dogs, unless they ask you to. It's sort of like criticizing someone else's taste in clothes. Sure, it might be tangentially relevant to their taste in artwork, but it's not nice and is likely to offend, so don't do it.
3. All generalizations are always bad. Really, generalizing people into various philosophical "camps" is just itchin' for a fight! If there's no "us" vs. "them," then it's pretty darn hard to fight about things. Look for common ground and acknowledge it when you can. Even if it's just little dinky things, like 2 people both agreeing that dogs need to be taken for walks.
4. Qualify your statements. "In my experience..." "With my dog..." "For example, with these 15 specific dogs I worked with, what worked was..." it makes you sound less arrogant and also gives people less leverage to attack you, since you're only stating what you believe/feel/have seen and aren't trying to say what is right or wrong for everyone.
5. Don't write posts when you're angry. If you're upset about something, walk away, and if you still care a couple of hours later, write your response then. The anger carries through even if you don't mean it to, and it does little more than feed the flames (that will come back to burn you, and make you even more angry - at least in my experience).
And one more as a "bonus" (lol) - if you screw up and make a post that's less than angelic, (wo)man up to it and just apologize. Even if you were "right." What you were saying might have been "right," but perhaps the way you were saying it was not.
This has been a public service announcement from the Sick of Reading Petty Bickering society. 
Please feel free to add on to the list, but if you are mean in this thread, I will resent you eternally and will never ever make nice comments about your dog photos, ever. (So THERE.)