Originally Posted by Marc Sabatella
Configure your AF button to cancel AF. Then you can take picture at any time by pressing that and the shutter.
I actually do the opposite of this. I keep my camera in continuous focus mode, disable autofocus on the half press, and use the AF button to focus.
This way, I can get the focus right using the AF button (or manually if the lens supports "quick shift") and then I don't have to worry about the camera trying to refocus every time I press the shutter.