Also, the focal length setting will affect DoF slightly, lower values will give you a bit more wiggle room with DoF range. However, linear perspective will be stretched which sometimes is useful for moving the background a bit further back from subject and bringing peripheral objects into wiew. My personal preference is to use a focal length of 45mm to 50mm. Experiment with different settings for focal length, focal distance and f/stop.

The lower f/stop values will give you more blur but will reduce the focal range, higher values will do the opposite.

Also, the f/stop values in the Tone Mapping menu have no effect on DoF and vice-versa. I mention this as it has been a cause of confusion.

Good luck in your adventures with DoF and if in doubt, experiment.