In my experience being productive is more a matter of setting a clear scope of goals on which I'm going to focus on the next X months. Other than the strict necessary tasks that might interrupt activities related to these goals, no extra goals may be added until one is finished. After that, at the beginning of each day I decided what micro-tasks I want to do (write paragraph X of paper, fix bug Y in project Z) and I don't go home until I am done. Everyday it seems like I am only doing small tasks but after time these tasks add up and I finish big projects. Big projects/goals are not finished over night, you need time. It's easy to get demotivated when there are big tasks ahead. The key is to chop them into do-able, reachable tasks and you hold yourself accountable to fix these tasks no matter what.
