Perhaps the following ideas are outside the scope or the original question. But in an ideal world, I think it would be useful to make the question editing window a bit more interactive for first time or beginner users. It is already the case that when you type the title of the question, the site dynamically matches the keywords in it and brings up links to possibly relevant past questions. Obviously, such functionality could be greatly expanded. Here's a list of dynamical suggestions the user could see depending on what they are typing into the question box.
Reminder that it's nice to use your real name or an easily recognizable alias (no value judgment here, just thinking of any alternative to 'user####'). Though, the question box may not be the best place to do this.
Reminder that formulas can be typeset using LaTeX notation (link to documentation if the user is not aware how). In the same vein, remind about basic Markdown syntax/features.
Suggestions for potentially appropriate tags. I can imagine a "latent keyword" approach here, based on the question text and how the existing tags match up to the extensive existing question database.
If there's any hint of homeworkness or of an uninformed elementary question, explain the scope of MO and that there exist other SE sites where the question could be asked (math.SE, stats.SE, scicomp.SE, cstheory.SE, etc.).
A small checklist of ways to improve the question (question clearly stated? reference included if needed? your level of understanding? type of answer expected? etc.)
Some words about how to interpret reputation.
In the ideal world that I have in mind, these suggestions would be raised automatically, possibly by a clever AI/machine learning component integrated into the sate. Then, as the user gets more acquainted with the site (by some metric, e.g., reputation), the suggestions can be phased out.
These are all things that currently the responsibility of other more experienced users, supplied in comments or answers as perceived needed. Sometimes, though, that kind of interaction feels aggressive and unwelcoming. I suspect that it would be received much more neutrally if coming from an automated system. Obviously, we don't live in an ideal world, but perhaps some day some of these features will be implemented by the SE platform.