Knuth introduced the notion of badness in his typesetting algorithms, well knowing that one cannot achieve perfection in typography, but rather both the algorithms and the author should strive to minimize badness. So here is my interpretation of an overall badness!
- Overful boxes
This should be considered almost a cardinal sin. If you have code or words sticking out in the margin give yourself a badness of a 300.
- Fonts If you are using more than three different fonts in your pages, give yourself a badness of a 100. If you are using the standard class headings give yourself a badness of 50.
- Too much or too little grayness Too much leading, too heavy or too light fonts, over emphasizing words with bold and rainbow colors for code give yourself a badness of a 100.
- Tabulars and boxes Too many tabulars, especially if they are enclosing data into grid prisons, fancy boxes with gray backgrounds, tables that you have either to turn your head or the book to read them properly give yourself a badness of 100.
- Spacing around page elements inconsistent spacing around equations tables and figures, mixed paragraphs some indented others not, give yourself a badness of a 100.
- Too much numbering, too many bullets Human brains mostly ignore numbers before text sections; sometimes the rat-tat-tat... of lists and enumerations in general text should be avoided. Give yourself a badness of 50 if you have no valid reason to number your sections.
- Rivers If you have rivers in your text, give yourself a badness of a 1000 and start typesetting your books with (all)TeX.
- Flushbottom Give yourself a badness of 20 if you use ragged bottom.
- Widows and Orphans Ignore both of them until your final version, if a widow exists after your final version give yourself a badness of 50. If an orphan does give yourself a badness of 50.
- Quotation marks Avoid them if you are writing in German or accept a badness of 150! Too many quotes and quotations give yourself a badness of 300. This is not so much a typography rule, but if you cannot express your ideas in your own words ...
- Business Reports If you managed to have your logo on every page and headers and footers in boxes, give yourself a badness of 500.
As you will observe if you are writing for yourself, i.e., you are not typesetting a thesis or the like you can control badness down to very low limit by judicious manipulation and a little rewriting during the final stages of a manuscript, so I would say a badness of around a hundred should be acceptable. If you writing a thesis anything goes so relax and let LaTeX do its job.