Well the season is over, what is NEXT?
The first thing to do is take some time away from football to refresh your mind and rest the body.
After a few weeks away from the game, start going through the game films from this past season. Start breaking down the film and determine which areas you had success, and which areas failed you.
Make yourself a list of areas to improve, then outline specific ways to improve.
For example: If the biggest problem all season was missed blocks by the Offensive Line, the research better blocking drills, re-work your blocking scheme and be sure to focus more time on blocking during the next season's practice.
The offseason is also the time to rework your playbooks if needed, research new offenses and defenses.
Once you have determined the style of offense & defense you want, take a look at those game films, will the teams you played last season be venerable to your schemes?
The offseason is the time to re-work the failures, improve on the successes and rest for the upcoming season.