For keeping track of tasks on my projects i use todo txt. For each of my projects will drop a file named todo.txt in the root. each line is a task, and i order them based on priority. I can walk away from it and when i start working on the project again, i have an simple way to see the list of tasks i have laid out for this project.
I personally find it less useful to see the “big picture” of all tasks, and this lets me focus on the details of my projects without forcing a bunch of structure.