We've probably all had some advice given to us that we've laughed off or cringed over. I've had plenty.
Here's one thing that drives me nuts: Give your characters a tick, a speech impediment or a limp or some annoying habit that makes it easy for the reader to track them.
Because readers are stupid and need cheap gimmicks to just help them keep characters in line? Because you're a lazy writer and can't distinguish your characters any other way?
I remember one comment on something I'd written: "They all run and jump the same way." You know, in some jobs, there isn't room for creative flair. Evil Kev can tell you from military and firefighting training that you get taught to do certain things a certain way. Sometimes, your life depends on it. If I was writing about police, soldiers or firefighters (and I was writing about one of those groups) I'd expect them to move in a similar fashion.
I'm guessing comment #2 is another way of saying #1 - give them physical differences that separate them. (Because one being a man and the other being a woman isn't enough.) So instead of writing a believable book I should give one detective a permanent disability that will physically define them the whole way through the story?
Guess I find that rationale lazy. And when I read stuff like that it feels artificial, contrived. Drives me nuts. Anyone else been given any advice or read something in a review that they thought was ridiculous commentary?