Knowing what you want to get out of training is the most important guideline. Once you figure that out, find the exercises/drills that are needed to reach those goals. Then take into consideration progression, proper recovery time, and balance. When I plan workouts for my teams and players, the first thing I ask them or decide myself is what I want to improve or maintain. Unless you have unlimited time, there is going to be some give and take, so knowing what is most important helps keep you on track when deciding what to include or exclude. If you are weight lifting, make sure to have a balance with everything (and there are different ways to structure the workouts depending on your schedule and preference, such as lower body or uppper body days or push or pull days). Each area you lift requires a day or two recovery time. If you do plyometrics, 2-3 days recovery time is best, depending on what you do. Those are some examples, I hope they help you. Remember, there is no perfect workout. If there was, it would be the one thing that everybody does, so it comes down to what you want.