This, of course, only works when I will continue in the project. I once had to hand over a project with some code I had put together the previous week, to a just hired, more expert employee who was going to "perfect" the project, and it was not a pretty situation. By that time I knew the data very well, and the new person did not, but had to be made busy. I felt not just embarrassed, but also that the whole thing had been a waste of time for everybody.