Find a location with good light for a portrait shot. Place your subject some distance in front
of a simple background and select a wide aperture together with a moderately long focal
length such as 100mm on a 35mm full-frame camera (about 65mm on a cropped-frame
camera). Take a viewpoint about one and a half metres from your subject, allowing you to
compose a headshot comfortably within the frame. Focus on the eyes and take the shot.

I think this exercise worked really well, with my subject in full focus and the background blurred out, even with the really bright light conditions.