Here's something that still bothers me to this day. Back in my high school days, I remember one teacher telling us that while we were writing our essay's to never have two sentences that began with the same word in one paragraph. I've read many of books, mostly dairy/journals and autobiographies, that often began sentences with "I" in a majority of paragraphs so I'm wondering who is right. Personally, I kind of see what the teacher meant with that because saying, "I" in just about every sentence makes the paragraph sound redundant.
Overuse of the same word/phrase can make your writing read badly, but there are certain instances where it is inavoidable. Given that every sentence, by definition, needs a verb, you will find yourself repeating I/he/she . . . over and over again. Its not a huge problem. Repeating unnecessarily is where the problem is.
I agree with Arron. Also, watch out for trying to find synonyms for a word when you shouldn't. Having to write "he said" more than once is fine, or at least better than trying to write "he ______ <--- insert silly synonym there."
Not so good: A bit better: By removing the constant references to the main character as observer, I let te reader become the observer, and rid myself of several repetitive I pronouns at the same time. Turn the focus outward from the character.
Right. When this gets difficult is when you have several action sentences in a row, where the MC "I" is doing something. Then it is not as simple as removing filters, like I saw and I heard. But you can still break those up by subordination and starting sentences with phrases.
