This is related to Decision on rejected edits should be displayed as a notification to the editor
...but my feature request is hopefully less contentious.
I am a new user (I joined last year, but just did one post then, I think, and just started up again now), so I speak from recent experience when I say that feedback on suggested edits is lacking.
I suggested multiple edits that were rejected for the same reason, and that happened only because I did not have a chance to learn the reason for the first rejection before I made the other, similar requests. The only reason I even know the reason now is because I decided to comb through all areas of my profile page.
Having loud and clear notifications for edit rejections across the board, which was discussed in the question linked to above, divided people, so I propose a more minor change:
I suggest clear notifications be provided for any user's first few edits (or at least the first one) rejected. Of course, since users would not be able to count on those notifications showing up indefinitely, the notification should also clearly mention that such notifications will eventually stop.