Right now I use something akin to GTD for my projects and goals. But in your case, I'd skip GTD because it breaks everything down so deeply, and you probably don't need that level of detailed planning.
First, I would decide on a goal to accomplish. Next I would brainstorm ways I could make that goal a reality - what resources do I need, time it takes to complete the goal, and so on. Then I would set up a plan of attack to accomplish that goal, and adjust it as much as needed.
For example, suppose I wanted to be fit by June so I look great in a bathing suit! My goal might be "lose 40lbs by June 1st, 2008". Next, I would brainstorm ways about how I could achieve that goal. I could buy exercising equipment myself, join a gym, hire a personal trainer, give my diet a complete overhaul, and so on. After I did all the brainstorming, I would sift through ideas and pick out the most useful and applicable ideas (joining a gym and changing my diet), and schedule out a way to accomplish losing the weight (exercise every other day and eat 1200 calories a day.) I would adjust my plan as I went along (not losing enough weight? cut calories or add more exercises).
Makes sense? Hope that helps you!
