Quoting to end

When the last word in a sentence has quotes at its end, where does the preposition mark go? Before or after the quote. I've always placed it before the quote, which looks ok with commas and periods but not so OK with ? and !. What if your sentence ends with a quote that has a preposition mark of its own, such as ? and !. You probably won't place any mark other than that belonging to the quote to avoid confusion such as "indeed we do!". But then again, hard to say.