Have a long-term list and a short-term (weekly or daily) list so that you are able to plan for things in advance. When the items on the long-term list come up, put them on your short-term list, but this way you won't be surprised by anything in your schedule.
Once you've completed an item on your list, check it off. That way you'll know that you actually did do it and you won't be in a dither trying to remember whether you've completed each step of a certain list item.