As you get older as a doubles player, you will get to a point where you think you are too old and too slow. Your greatest enemies are the short ball and the wide angled ball. How can you make an adjustment for these problems without going to the gym or going back in time?
 
Try this! After you serve or return the serve, immediately move to an "imaginary spot" approximately 2 feet inside the baseline and intersecting the outside singles line.
 
What will this do? Most players move a couple of feet behind the baseline after they serve or return serves. So, by moving 2 feet inside the baseline, you will be 4 feet closer to the short ball. By being near the outside singles line you will be at least 4-6 feet closer to the wide angled balls. Remember how many times you almost got to the ball? This will be a great aid. The "imaginary" spot you go to is not a hitting position, it is a "get ready to go" position. If they return the ball deep you can move back, if they hit it short or wide you will be closer to it and if they lob it you can volley it.
 
Remember: go to your "imaginary spot" between shots if you are staying back near the baseline.
 
Good luck on the Courts!