Sometimes you've read the good question guidelines but if you're new to the site, your question may still not be up to the site's standards. Which will usually trigger less-than-polite responses from annoyed longtimers and possible downvotes. This is very discouraging for new users, so how about a place where you post your question draft and allow people to give polite feedback before you post it to the main site or decide against posting?
I hope this isn't too similar to beginner tag suggestions. The difference here would be you specifically request your question to be reviewed for quality, and are not expecting answers yet. This would also declutter newbie questions from comments that are about the question quality rather than the question content.