urgent capitalization issue

So in this phase of my story I'm often referring to characters by their occupational titles because there is a cast of thousands and most of these people walk on, deliver some portentious lines or do some portentious deed and walk away never to be seen again, or only to be seen again once or twice more.  However, there are some more enduring and sometimes more important characters who seem to be most conveniently referred to in this way too.

This leaves me confused as to when to capitalize the label. Obviously if it's descriptive it doesn't get capitalized.  If it's part of a name -- Lieutentent Kargburn -- it does.  If it's in lieu of a name, though -- as in "The Lieutenant is always like that" -- as opposed to when it's purely descriptive -- "there was a lieutenant in the wagon" -- that's a little less clear. Because sometimes it's sort of both. "The corporal emerged from the office, saying 'The Lieutenant will see you now.'  . . ."

I need more finely-tuned guidelines for capitalizing these things, because I think I'm being rampantly inconsistent at the moment.

You guys are no help

The consensus on my urgent capitalization issue is to stop fretting about it.

foo.

Well, I'll fret if I want to, but I'll stop going back and attempting to correct inconsistencies, then.

"let the copyeditor deal with it --" that's assuming that this one, unlike every other book I've ever written, will ever get farther than the slush pile.  Yes, I'm pretty sure I'm writing a better book than I've ever written before, but, you know.

what have you chocolate cakelike, for future reference

Personhead cattails gave me a recipe for eggless chocolate cake but when I set out to make it this morning I was feeling kind of belligerent with the food and I made something quite different so I am writing it down here for future reference.
( long recipelike food ramblings. you will be bored or annoyed, one or the other. )