READ OUT LOUD. Choose which marked text you prefer to practice with - macrons or accent marks - and read the text out loud until you feel comfortable and confident. Then, try reading the unmarked text at the bottom. It should be easy for you after practicing with the marked texts. :-)
MACRONS. Here is the text with macrons:
Ūnusquisque nostrūm duās gestat manticās - alteram ante pectus, alteram ā tergō, utramque vitiōrum plēnam; aliōrum quidem anteriōrem, prōpriōrum vērō posteriōrem. Proptereā hominēs sua vitia omnīno nōn vident, aliēna vērō perspicācissimē.
ACCENT MARKS. Here is the text with ecclesiastical accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Unusquísque nostrum duas gestat mánticas - álteram ante pectus, álteram a tergo, utrámque vitiórum plenam; aliórum quidem anteriórem, propriórum vero posteriórem. Proptérea hómines sua vítia omníno non vident, aliéna vero perspicacíssime.
UNMARKED TEXT. Here is the unmarked text - after practicing with the marked text that you prefer, you should not have any trouble with the unmarked text:
Unusquisque nostrum
duas gestat manticas -
alteram ante pectus,
alteram a tergo,
utramque vitiorum plenam;
aliorum quidem anteriorem,
propriorum vero posteriorem.
Propterea
homines
sua vitia omnino non vident,
aliena vero perspicacissime.
IMAGE. Here is an illustration for the story (image source) showing the mighty Zeus:
