I have a few things I always do:
Go to the gym more (This usually lasts through the Derby and tapers off by late summer)
Eat better (pretty easy to eat better than the eating I do between Thanksgiving and New Years)
Lay off booze for about a month (again drinking becomes a daily thing during the holiday so I hit reset on that habit)
Some things I want to do this year:
Focus on becoming a better golfer (add new shots to my game, add consistency to the shots I already hit, work on short game more during practice time)
Take a 3-4 day trip with the entire family
Take a 3-4 day trip with my wife