How to deepen 'black'
 

I shot some footage which is pretty dark (mood) but a bit too dark. I upped the lightness and contrast, but the black still looks a little washed out, but the brightness level is perfect now. How can I ramp the black back to being black.

I don't know what NLE you are using, so it's impossible to give a detailed answer, but basically, by raising the brightness, you raise the luminance of the whole picture, and can bring the black level too high. Look for "black level" or "setup" in your colour corrector, and try lowering it.

Or instead of using the brightness control, play with the "gamma" instead. This will leave your black and white levels the same, but adjust the distribution of luminance values in between.

Sharpen the contrast too can help.