Rounding off the guidelines:
* Setting Audio/Video questions: All too often, we see quizzes where there are mandatory audio-visual rounds and the questions may be set thus: A pic(song) is shown(played). After some brain-racking, the participants come up with their guesses. Then the quiz master goes on to reveal the pic/song and the real question is indirectly connected to the pic/song. The problem with this is the pic/song isn't central to the question. The q may well have been asked without the pic/song without diluting its focus. So when setting a audio-visual qn, ask yourself whether the qn could have been reframed without the pic/song & still have all necessary clues/focus to it. If yes, chuck the pic/audio. You don't "need" to have an A/V question in the quiz. Any deviations from plain text need to make significant contributions to the question.
* While conducting a quiz, try & do away with time limits to answers. Working out requires time, give that to your participants. I guess, after taking the effort to make the qns, u do want to provide all conditions for the qns to be attempted in the best possible manner. One can be a good judge of time, a wayward answer can be dismissed fast & a answer that is being worked out correctly can be given the time to proceed. Working out answers is sometimes like tugging at the loose thread in a sweater. A decent yank & the whole thing unravels magically. That's mostly the kick in answering such qns.
*Setting qns is also a matter of fairness. Niranjan mentioned this in context of covering as many fields as possible. This gives everyone in the quiz a decent spread of qns to answer. Some qns will be cracked only by the domain experts. But many should be able to atleast take a decent guess at most qns. Fairness also applies to the amount of hints one hides in the qn. This is a judgement call to be made by the setter: Too many clues make the qn easy, too less & u lose workability, Also lesser the clues & the domain expert is happy (no one but her/him will be able to answer the qn). Make the q such that the lay quizzer will be have a decent chance against the expert in that field. Niranjan made a bar graph of question areas couple of yrs back at Mensa to note the spread of fields. Analysis like this gives one perspective on the quiz.
*Try & set many quizzes, small & large.
*Use the quizzing books, sites to help u set qns. Don't pinch qns, reuse them. There is a difference in plagiarism & inspiration. The trivia from such resources can be used to set connect qns et al. At least reframe. It's pretty humiliating when the other quizzers find out (& generally they do) the "dhaap"-ed qns.
*Pay attention to how others frame qs in their quizzes. Ask for & take home a copy of the qns from a quiz. Most decent quizzes are happy to give u a sheet. Don't mug the answers, read the qns & think about the framing.
And slightly digressing:
*Go to a quiz for the qns & not only for the moolah.
* If u don't make it thru to the finals, stay on to watch them. You still learn a lot this way.
* Quizzing & setting are pretty much artistic endeavours. One doesn't get it right at the first shot. Plug away at it constantly. Don't approach it very academically.
* Quizzing is also about pocketing little pieces of info in some recess of your mind. You may have to use it not in the next quiz or the one after it, but some day deep into the future. Try & make sure you don't pull a "Karna" then by forgetting it :-)
* Once u start putting a tag of quality on ur qns, u'll find that its difficult to compromise on even 1 qn.
* When u find the same trivia cropping up, try & use connects to reuse well-known trivia.
* Pay attention to standard trivia, these like "singles" in cricket are an easy source of points. They are also useful in setting qns. A qn leading to standard trivia, but which is cleverly framed in a novel fashion, will draw applause from the experienced quizzers.
* Asking questions is like reciting "shair-o-shairi". The spontaneous "Wah-Wah" that a good work of art receives is all the encouragement & pat-on-the-back that u will need & enjoy.