I’m going to be starting a bed frame and headboard project soon and had a couple of questions regarding using the Kreg Jig pocket hole system to join soft woods like pine to hardwoods like maple or oak. Should I use the coarse screws, the hi-lo screws, or the fine screws?
Also, should I have the drill clutch set low, medium, or high (or not use it at all)?
Gary is exactly right, you'll want to choose the thread type of your screw (coarse, fine) based on the receiving workpiece (the one without the pocket-hole) which will actually be engaged with the threads.
Clutch settings are harder to predict based on variable wood, variable drills, etc. Some prefer not to use clutch settings at all and just 'feel' the screw secure, others like to set it and forget it. Trial and error on test workpieces may be your best bet.