A very powerful, but one of the most non-intuitive agile practices is pair programming. Before one has tried to get good at this, it seems unbelievable that it is actually is better and more efficient for two people to work side by side on the same problem than having two developers working individually.
If you want to get some inspiration and courage to try pair programming, check out this often referenced scientific study of the topic: http://collaboration.csc.ncsu.edu/laurie/Papers/XPSardinia.PDF
“Abstract: Pair or collaborative programming is where two programmers develop software side by side at one computer. Using interviews and controlled experiments, the authors investigated the costs and benefits of pair programming. They found that for a development-time cost of about 15%, pair programming improves design quality, reduces defects, reduces staffing risk, enhances technical skills, improves team communications and is considered more enjoyable at statistically significant levels.”
There you have it: The extra time of 15% that is spent when pair programming is paid back 15-60 times by reduced test costs, depending on the organization. So, pair programming is profitable, good for quality, increases work morale and builds teams.
So, if you have not done so already, go ahead and try now.