>> One additional technique I learned from others is to use submissions to conferences as a way to get feedback on your work without any expectation that it gets accepted. You do that early knowing there are flaws, but do it to get early warnings from reviewers about rejection points.

This is, of course, one if the problems with current research as it wastes everyone's (yours, reviewers, ACs, etc) time. In particular, because you're not guaranteed practicable or actionable feedback and because you're increasing the time reviewers must review work (i.e., more papers to review as submissions are higher and quality lower).