You can't improve what you can't measure. As a salesperson, it's vital that you keep accurate records of all necessary stats - UPs, demos, T.O.s, write-ups, sales, gross, closing ratio, etc. Having good information will help you determine what you're doing well; but more importantly, it will highlight areas where you can improve. So if you're talking to 50 people in a month, but only demo 6, you know that you need more work on your demo skills.
Here's how to stay on top of your statistics: