Are there specific guidelines for when it is appropriate to flag a question vs. voting to close?

Increasingly, voting to close a clearly off-topic or otherwise unworthy question and posting it in the "Vote to Close" chat room yields insufficient votes to finish it off, unless a moderator happens to be watching the VTC chat.

I find myself extremely hesitant to flag such questions unless there are special circumstances (e.g. belongs on a site with no migration path), because I presume that the very existence of the "vote to close" chat room is to discourage flagging of questions that can be voted closed.

This leads to cycles of voting to close a question, posting it to VTC, waiting at least 8 hours, and then flagging it with a note that I tried the other route first. This strikes me as a highly inefficient way to engage in crowdsourced moderation.

 * Is the vote-to-close chat room working better (or equally poorly) for others?
 * Is there a better way for me to approach questions that deserve to be closed?