To improve your ability to maneuver your racquet, try using a smaller grip. As I've aged and lost strength (I'm now 67), I have found it more and more difficult to manipulate the racquet as I'd like. When I was young, I used a 4 5/8 grip. Then I dropped to a 4 1/2 grip. Recently I took a chance and changed all the way down to a 4 1/8 grip.
The results have been remarkable for me. I am now wielding the racquet with the same dexterity I did when I was in my prime, and I'm finding that I hit the sweet spot far more often. I've even regained a few miles per hour on my serve, according to my regular opponents. I am also able to hit with more spin than ever—although that, of course, is the result of a combination of new grip size, racquet technology, and high-tech strings.
I made this change after hearing that Rafael Nadal uses a grip that is very small for his hands. I would suggest that Roger Federer do the same thing as he's aging, though I doubt that he will listen to me. The only drawback to this is that not all racquets on the market come with grips as small as 4 1/8.
This may not work for everyone, but I suggest giving it a try. I suspect that it will work for young players who haven't achieved their full strength yet, and for older players like myself.
Ed Weathers is a former instruction editor at TENNIS magazine.