Almost everything about XP except for pair programming can be done by a solo programmer.
One of the first concepts I started using was "Do the simplest thing possible." In the past, when I developed classes, I had often added functionality that was not needed and might never be used. Now, when I create a class, I try to follow that concept. Write enough code to do the job, don't add anything that doesn't immediately contribute to the functionality.
You can also implement unit testing as well. That's another feature of XP that I have started doing. However, you have to truly be a solo programmer for this to work. What I mean is that if you are on a team but everyone programs solo, then doing unit testing will not be much help if the others on your team are not also doing unit testing. When others make changes, they won't run your unit tests, and they won't know if they've broken functionality elsewhere in the system.
I have also tried using CRC
cards recently. I don't know if I'm using them properly, but they seemed to help me understand a system I recently worked on.
Kevin Mukhar
[This message has been edited by KMukhar (edited December 15, 2000).]