I have seldom done it well. Normally one person rushes off to "just quickly try this idea", without really explaining it ("just wait a minute, it will be quicke

I have seldom done it well. Normally one person rushes off to "just quickly try this idea", without really explaining it ("just wait a minute, it will be quicker to just type it in than explain it") so the other person is limited to basically spotting errors which is slightly useful, but probably not the best way to spend a second programmers wages. It excels in combination with TDD. One person writes a test, and the other person makes it green and writes the next test and so on. Combining those two practices is very powerful. Another time I don't like to pair is when debugging or trying to understand some old legacy code or something. If two people have different strategies for doing that it doesn't really make sense to pair. I like to write a lot of stuff down on paper for example, another guy likes to click "step" in the debugger on a lot.