A more extended version, if you want to take the time to do it, could include sending yourself an email at the end of the week with what you did, what you plan to do, and your problems. That way you can keep track of what you've accomplished, and your plans. It's pretty helpful if you need to go back and figure out when you did something or where your time's going.
But if you're having trouble with planners and stuff already, just try using a whiteboard.