No matter what billing method you use, if you are tracking time in Office Tools Professional there are best practices that need to be addressed. You should track your time as you are working as often as possible. This will ensure you have the most accurate record of time worked. Utilizing the Activity List is the absolute best way to keep the most accurate time. Complete events that are assigned to you, as you finish them, from the Activity List and plug in your time to the time card that is automatically generated.