Work breakdown structure or WBS is the one of the most powerful methods for task management. It has been used in successful large projects in aerospace, constructions, manufacturing and many other fields. In a nut shell, WBS is a method for breaking down larger tasks into smaller tasks and refine those smaller tasks to even smaller ones called sub-tasks, until each sub-task is totally understood and could be estimated with a high degree of certainty. This is top down approach in task management and its benefits are well documented.
Binfire is one of the very few task management applications which supports WBS to sixth level (the maximum recommended by PMI). Using WBS in Binfire, you can breakdown a large task to its smallest components, estimate the duration for each one of those small tasks and use dependencies to make the tasks interrelated. The application automatically calculates the start and end date for each one of larger tasks (or container tasks). All this could be graphically manipulated in the interactive Gantt.
Give WBS in Binfire a try! It will help to have a much better task estimates for your projects.
Be as productive as you can be!