Derek Jeter just suffered through his worst offensive season of his career. He wasn't much better in the playoffs (though he faced great pitching). As he enters the twilight of his career, of course, this is a major concern for what he means to the Yankees experience. After watching the Captain for many of his at bats this year, this Fan is bold enough to make a few suggestions.
At his age, reaction time slows. That is natural in the course of events. With diminished reaction time and a slowing of his ability to react to what is being thrown his way, Jeter needs to simplify his approach. It would be similar to what Nick Swisher did this year. Swisher was very "noisy" in his approach with a lot of movement before the pitch. But staying "quieter," he had a better ability to approach his swing.
Derek Jeter has a wild waggle with his bat when he is hitting. If you watch, you'll notice that he not only waggles his bat during his set up, he also waggled the bat forward over his head and toward the pitcher just as the pitcher is starting to throw the ball. This is something that Jeter has always done as a timing mechanism and it has worked for him. But he no longer has the quickness to get away with it. He has to get the bat all the way back to the hitting position from in front of his body and then swing forward even as he is reacting to the location of the speed and location of the pitch. It's just too much to accomplish when his motor receptors are slower.
What Jeter needs to do is get quiet like Swisher, like Paul Molitor did late in his career, like Carl Yaztremski did at the end of his career. Doing so would give Jeter a more even approach to the pitch, keep him more balanced and give him more time to react to what is coming toward him.
One knock against Jeter is that he's not very coachable. While the Yankees' batting coach has had great repore with A-Rod, Swisher and Granderson, you never see Jeter talking to him. It's time to change that and have a couple more good seasons before wandering off into the Hall of Fame.