Time sheet records = Revenue billed
Complete your time sheets daily, every day.
The best practice is to keep a running log of time (software-based or otherwise) of everything you do as you do it. If you’re a scrap-of-paper person, then you need to aggregate and compile the list for your billing program before leaving the office that day. Even if your memory rivals that of the elephant, you will miss things if you don’t do this every single day.
One missed 10th of an hour each day translates to 23 lost hours a year. And failure to keep current, proper time records will usually result in more than just 1/10th of an hour lost … DAILY … and MANY thousands of dollars in lost billable revenue!