If it's not a trade secret, explain what the problem you're trying to solve really is, and why you're trying to solve it in the first place. If you're trying to move the moon closer to the sun so that it will reflect more light, and let you read Perlmonks at night, a fellow monk might point out that a nightlight is a simpler solution. :-)
Explain what options you're not willing to explore, and why. "The boss hates Mysql, so we can't use it", "Postgress support for mythic widget X is still in beta, so I don't want to use it", "I only understand SQL Server, so that's what I want to use", etc. This helps fellow monks understand why you're not interested in the "buzz-of-the-week" technology; otherwise, why shouldn't suggest you go with "popular wisdom"? In a sense, that's what you're asking for when you ask a large group of people a question.
Repeat yourself. Write the main point of your article in the introduction, explain it in detail, and recap the main thrust of the question in the summary. That way, you're less likely to get an answer to a technical side-avenue of your problem, while the main point remains unsolved.
Learn to evaluate responses. Monks abilities vary widely; and this includes the self-assessment ability as well. They may think answers are right that aren't, or misread your question entirely, because they know the answer to the simpler interpretation. Be patient with these monks: they're usually not doing it on purpose, they just make mistakes, like all of us. Remember, you're not paying these people to help you: they're volunteering their time, and giving their best effort, and even the best people slip up now and then.
Explain the options you've tried, and why they didn't do what you want. People are more willing to help when they know you've tried. If you're struggling with how to code something, post some sample code that demonstrates the problem, with sample inputs, and expected outputs. If you're struggling with something more abstract, explain the lines of reasoning you've tried, and what you liked/didn't like about each.
Communicate with people. Thank fellow monks for responses; even if they're wrong, they still tried to help you out. Friendliness helps build our community and encourages people to post. If someone has lost track of the original idea, polite follow-ups to clarify why certain suggestions don't work, and what you'ld really like to see happen.
Don't expect miracles. This is a free site: and sometimes, the expert who knows the perfect answer to your question might be sick, tired, or on vacation. We've got a lot of talented people here, but they get busy. Be patient, and hope for the best.