After a day's shooting I will "reset" my cameras to a general setting of ISO 100 and a low aperture of f2.8 or so and also check that auto focus, white balance, focus point, metering mode etc are all reset to how I like them for general shooting. That way I know that if I need my camera in a hurry I know what all the settings are at and I need only adjust shutter speed and maybe ISO which takes no time at all.
However, if I am not in a hurry, I will set up the camera for the style of shooting that I am using.
Usually, I will first set my aperture for the depth of field that I require, set my shutter speed to ensure my shots are blur free and if I can't get the shutter speed I want I will push my ISO up until I can.