I'd like to see a whole lot more restraint exercised when it comes to the closing of questions.
The grace period Brian mentions is a fantastic idea.
Aside from questions that are very obviously off topic, such as the (now deleted) questions asking for a copy of P.T. Barnum's work or questions on original research or offensive questions, questions should be left open. If a question has sufficient downvotes and/or closevotes and/or many critical comments then that is the time for a mdoerator to take action.
I had my question on Simian Lines closed yesterday as a moderator found a paper finding a link between simian lines and race and from that somehow inferred my question had racist overtones. The question was opened fairly quickly after, although it shouldn't have been closed in the first place.
Likewise my question on people having a distinct/unique look to a specific region after generations in that place was closed. This question should have been downvoted or edited constructively rather than closed. Looking at the comments and upvoted a lot of people find the claim notable and interesting enough to answer.
A question on meta asking if the site should have firmer guidelines so it is easier to justify the closing of questions was itself closed. This was on meta, a site for discussion about the main site. Further discussion is now impossible on that question, with no adequate justification being given.
While I am using my own questions as examples here my answer should not be taken as an extended complaint. I think they are good examples of questions that are closed and only hurt the community by being closed.
Often the justification given is that a closed question can be reopened by the community. I don't think this is a good attitude, as many users will not have the option to vote to reopen and users who do may not want to waste a vote. When a question is closed it also tends to "disappear", making it hard for people who would be interested in it to find it.
In short, I feel moderators should adhere to A Theory of Moderation. To quote:
But what do community moderators do? The short answer is, as little as
possible!
I take this to mean interfere only when necessary. As far as closing questions goes, this should mean only closing questions that are indisputably offtopic or offensive. When it comes to issues such as notability the guidelines are vague, so restraint in closing should be applied.
For the most part closing a question that has upvotes and that people are interested in precludes any possibility of a good answer, which is hurts more than it helps.
That is the policy on the other SE sites in my experience. I have no idea why it doesn't appear to be the policy on Skeptics.SE.