I know as much as to get shallow depth of field, so the foreground is in focus while objects in the shallow background are blurred one needs to shot from a distance from the foreground subject with a high exposure, but would I go about shooting so that the background is in crisp focus while the foreground is out of focus? Expanding on that, how could I do a focus pull to alternate between the background and foreground being in focus?

By doing the same thing for the front focus but using manual focus

Paul