In a recent issue of the London Review of Books, a professional translator of French into English writes, "In the field of translation studies, it is a commonplace that that good English doesn't mind and often prefers repetition, while good French prefers and often insists on synonyms--a habit sometimes referred to in English (not always in a positive way) as "elegant variation." He notes that when translating, he frequently finds himself replacing French synonyms with English repetitions in order to create good English style. In writing programs such as ProWriter, repetitions are noted and implicitly discouraged. No proximate repetitions seems to be the goal. Aside from judging by ear, when should repetitions (he, she, they, a character's name, etc.) be excised?
I simply don't agree with the translator about repetition in English. Unless it is being done for effect, most words shouldn't be repeated within two sentences of each other and very few should be repeated in the same sentence (the main exception being articles). This is something I have taught to students as well.
Read your work aloud and to find repetitions that shouldn't be there. I spend a significant amount of time finding synonyms for repeated words.