"insert something witty here"

Guys, guys, guys.
I don’t know why you people can’t understand quotation marks.
Look, guys, quotation marks are not a replacement for punctuation. I do not ever want to see dialogue that looks like,

“do you have any idea what you were doing” He said

Furthermore, the normal rules of apostrophe and comma use, as well as capitalization, all still apply. The rules of grammar do not magically all turn off inside of quotation marks.

Punctuation at the end of the quote applies as explained in this post, but in dialogue everything should go inside the quotes anyway. At the end of a sentence that ends with a period and ALSO ends the quote, a comma should be used instead of the period. The subsequent word outside the quote, then, should not be capitalized unless it’s a proper noun.
Examples:

”I’m gonna go rob that bank! It’ll be great,” she said.

“Well that’s all well and good, but where’s your escape car?” he asked.

“Escape car?” she scratched her head, “What would I need with that?”

You see what I did there? Proper capitalization and punctuation.

Get it right!