We have users with varying opinions on using "vote-to-close".
Instead of muddying other questions with thoughts on close votes, let's have a question that is solely about Vote to Close.
Specific points to cover may be:
Bad questions are bad questions and need to be closed. It's not our job to fix them, nor should the history of a question have anything to do with its present value.
When you see a inappropriate question, vote to close it. When you see a poorly written question, downvote it.
Then you can ask for more details or request the OP fix something. If the details and fixes are forthcoming before 5 close votes accumulate, the close votes should stop and good answers should spring forth. If the details and fixes aren't provided, as it usually the case, then the close process will run to completion and the bad question will have been dispatched with minimal harm to the site.
Note that "bad question" doesn't mean just leaving out a one or two clearly identifiable and quantifiable parameters. These you ask for, and will probably get. "Bad question" means it will take at best a conversation with the OP to fix, not just the value of a few parameters to clarify the problem.
Try to help, and then only vote to close once hope is lost
Especially when the user is new and just needs some guidance on the format, it's a good idea to try to provide guidance first, or better yet, make an edit that makes the question better and leave a comment about it.
Good times to vote-to-close a question are if there is no possible way it could become a decent question, or if it has languished with out any effort from anyone towards making it a good question.
We have seen some new users that in response to feedback will delete their questions, and we've seen other questions that started out as mediocre and were turned in to decent questions through the revision process. These ultimately add value to the site, even if they're a little unsightly in the process. The users that come with them will also, for the most part add value.
One thing I'd encourage people against is a knee-jerk response to request more information without a purpose. For some very specific questions, we still need a lot of background, but other questions can be answered on the level they are asked. A good answer will introduce some context, explain what the major variables could be, and how the possible options relate. Not all questions will be fully developed design specs. If we need more information, let's try to specify exactly what and exactly why we can't answer the question as written.
