This is a question in the spirit of this one where I answered that it is important to keep track of what you have done something, why you have done it and what is not working. I personally use notebooks for that purpose, but it has several drawbacks: first I need a lot of storage surface, second when I travel I cannot access my data, and finally this is not collaborative. It has however a strong plus: the notebook can be used as the equivalent of a laboratory notebook (you just have to find somebody to sign each page...).
So, I am interested in knowing how other researchers proceed for that matter. For example, is there any specific software that solve all the issues I mentioned?