How to remove background noise from Audio RSS

We've all been there... you have a beautiful "looking" shot, but the location is in a "noisy" environment. "Back in the day", this meant you had to move your location to something more suitable for cleaner audio. (I guess if we're being honest, this is still preferable, but sometimes you are stuck with your location, and you just have to roll with it...) So what are your options?  For starters, mic placement is always important.  You want to get your mic as close to your subject as you can, without being in the shot, if it’s a boom microphone.  If your client...