Organization is the #1 killers of artists and developers alike. Programming wise, I get it functional, clean up the code and if something breaks I power off my machine, take out my HDD, drive to the river, push my car into the river and drive my HDD to the corner of OH FUCK and ME.
Couldn't put it better myself.
However, development wise I tend to use something like a Gantt chart to help break down what I am doing, and when it should be completed by.Â
This helps me to track project progress.
Though I suppose it depends on the project. Things like Trello are very useful for me! :)