I think the key's to a successful off-season are taking pride in your conditioning, making it fit, and being yourself.
1. As an athlete, there is a sport season, but you never take a break from being an athlete. In other words, and athlete needs to maintain their conditioning, strength and flexibility, and their skills year round. This does not take as much as most think, but it does take consistent aerobic conditioning, maintaining or building strength and flexibility, and spending time working on drills. We live in a culture where it is easier to brag about how much we are not doing versus how much we are doing. Be proud of your conditioning, maintain your strength, and work on your skills. Even if you do them in smaller chunks than you do during the season, it will make a difference. If you do the next two steps, you CAN be an athlete in the off-season.
3. Be Yourself. We have our swim-aholics, our cross-trainers, and our triathletes, and there is no right or wrong approach as long as you are working hard and enjoying what you are doing. I have had All-Americans come from all 3 categories. Bottom line is, there are many ways to stay fit, do what you like to do and be an athlete. What works for some, doesn't work for others, find something that keeps you moving and working hard and like the saying says "JUST DO IT!"