Since the actual football season is rather short, the most time of the year it's offseason, that is there are no games and usually not even football realated team practices. That means that practice planning for football is planning practice cycles:

• Offseason
• Preseason
• Inseason

Since the offseason is actually the longest period, the cornerstone for success is indeed already laid in the offseason practice. This also mean that you have to carefully plan your schedule throughout the whole year to be at the peak of your performance at the right moment: the competition-phase (Season).