Having a properly prepared to-do list to work from may be the best tool in your time management tool box. Use your to do list effectively and achieve more. With disciplined use, it can help you stay on track and minimize distractions.
The key to developing that list is to make sure that those items you highlight as priorities truly are the priorities. It is a sad fact that many people give a high percentage of low priority items a high priority status.
There are probably two or three big items at most that will make the biggest difference. Concentrate on them first. Review your list throughout the day and re-prioritize as needed.