Trolling is not only an art but it takes either a true comedic genius or a just a truly stupid comment to get things going. You have seen it in /trade, but here's a little video of what I have seen (this was a while back, so please don't mind the retro feel).
In my experience, my own trolling is nearly non-existent anymore, other than when I need a bit of a pick me up. I normally ponder to myself, curled up into a ball, in the darkest hallway in my house, safely rocking back an forth in a somewhat crazed matter. Then, I normally hit on a topic. Now you want your troll to apprear to be harmless in nature with severe undertones for the unknowing "answerer".
Something like "I cannibal once told me that clowns taste funny." is more of a light hearted troll, and now that I think of it, this wouldn't work too well unless you add the fabled "discuss" after. Personally, I think the use of that word, discuss, is for the amateur troll, and will most likely end in you getting nothing out of your well thought out comment on clowns.
Here is another video link on how to properly troll your audience (I recommend it to be a funny yet hillarious video). This is a must see for proper trolling techniques.....
I do however fall into the troll trap now and again, in fact my favorite fall was the "Why does my magnet not work?" question. I followed up with "you need to turn it around". Yeah. I am a genius. Sure.....didn't work, I was raped by the troll, catching me up with "I turned around, and it still doesn't stick to anything". Now I felt the kid was dumb, or just not understanding what I was saying. After a few minutes back and forth, I was hit by the troll hammer. I laughed, I cried, I envied him. I though that was hillarious that someone kept me going, all the while just busting up behind the glow of their computer screen...
There are other ways to troll by commenting on a topic/comment/subject. One that I can recall reading, I think it was at collegehumor.com . It was a question from a girl that says her boyfriends buddies come over and eat all her food, and make a mess. She is basically looking for advice on how to get rid of them without pissing off her ol'man. The troll kindly suggests "put some Beiber on the radio". It's simple but strategically placed comments like that one that make me totally laugh out loud. I guess it kinda goes back to my childhood when the big "trolls" were saying anything related to size, "thats what she said" or the answer to anything "your mama".....
Here's a few more of the cheesier ones I have seen:
"Is there really more than one way to make ice?"
"I was wondering how to ask a question here?"
And basically anything that starts with these can be a great troll tread starter:
"How do I...."
"When do I know I can....."
"Where is the...."
"What is the opposite of"
So for the next time that you want to troll, how about a "Can I ask you one question?".......you know what they will answer....."sure"......your turn now......"thanks". mmmmm. Trolling is good. Kinda cheesy, but good none-the-less.
And remember..."Never gonna give you up, never gonna let you down".
Your turn, feel free to troll on your troll stories. Don't be scared, it's okay..... =)