I am a relative noob to fish-keeping, but I do have lots of experience (professionally) in giving advice to people.
The key is to
never be condescending..This is what I find missing in the comments of most of these (recently un-banned) experts.
Let me correct that: Don't be condescending
if you actually care about the well-being of the fish and in educating the new-comer asking advice/making some mistake and do not just want to be a jerk showing off some esoteric knowledge.
Having said that, as a newcomer to "Monster Fish", the help and advice of all the experts on MFK has been invaluable in helping me keep my fish happy. And I hope they continue to guide the rest of us in the right direction.
Disclaimer: I was a CompSci post-grad (nerd!) before getting into Management ("professional bull****ting"). So that part about "don't be condescending" is a lesson learned from my own mistakes.
A simple tip: Please avoid over-use of this emoticon

unless it's self-deprecating or in good humor.