When I write a paragraph that largely has to do with internal thought or one person of each gender, I revert to using He and She throughout the paragraph. After having stated who He is, and who She is, I figure he and she are fairly well understood. Does this carry into every paragraph after until a new he or she is involved? Is there a limit? It feels... dry and clinical to write Alex and Theresa in the beginning of EVERY paragraph, like it's become a pattern of stating who it is when it seems very obvious.
No need to mention it at the start of a (every) new paragraph. You need to mention it if you feel the reader maybe confused about who you're referring to. If you feel the reader may be getting so confused, a more pertinent question might be: ' should he/she be getting confused at this point?' ...Do I need to recast the last (x number of) sentences to make it clearer (if clearness is my goal). As a rule, your readers are not morons. (Except when they are)
I figure on using his name for every four to five uses of he. If he's thinking about someone else, it's every time he switches back to himself, less when he's thinking about a female. It's more of finding a rhythm and tone. I'll usually tie the name to the most emotionally charged sentence of the paragraph and work outward from there.
Thanks for everyone's input! I've been operating as most of you have been suggesting, only reaffirming character names when either a new character comes into play, or when it 'feels right.' Typically I won't go more than two paragraphs without repeating the names, usually by way of dialogue or some other tool beyond narrative.
Mix it up. If you feel like a name drop would sound better than the standard pronoun, do it. If mentioning the name isn't really that important in the sentence, go without.
It carries until you think someone might not be sure of who He is. No hard limit, no. You could easily write a thick book without a single reference to the MC other than He. You seem to think this is a one sided hard problem, and it's a two sided easy problem.: - If with He it's clearly enough, don't use the full name unless you're going for a particular figure of speech. - If with He it's clearly not enough, use the full name. - In case of doubt, most people fall on the side of restating the identity. I try to remove the doubt by other means (as starting with action or thought that clearly only He could perform or think).
Having only one main female character in my current project, I've even started chapters using "she" since it's pretty obvious who it's going to be, if the subject follows on from the previous chapter. I only use it when I need to reaffirm who's saying what, and once or so in paragraphs with action in them, just when I think it'd sound better. Mostly, just play it by ear. Once you strip away all but the most necessary names, you can see where it's still uncomfortable to not use the name, even though no intervening character has come along and disturbed things.
No need to do it when it is obvious, Thansim has some good suggestions there. But it sometimes becomes necessary for clarity, like when you have two (or more) male/female chars in a scene. Yes, your prose doesn't look the best when you have to mentioned the names repeatedly, but it's a small compromise when you don't want the readers to be frustrated reading and re-reading the sentences to find out who is who.
I don't like using the character's name when it's a thought, and if I give the name it's at the start, not later in the paragraph, like: Jon sat down again. Why the hell won't she make up her mind, he thought. not: He sat down again. Why the hell won't she make up her mind, Jon thought. It seems kind of obvious, but I've read the second type of thing, and it looks really awkward.
don't forget that there are other ways you can refer to characters, besides with names and pronouns... such as 'the man/woman/boy/girl/old guy/young gal'/etc., ad nearly-infinitum...