For years I've been using the K.I.S.S. method, for those who have never heard of this it's KEEP IT SIMPLE STUPID! The customer only wants the end result nothing in between. If they looked confused stop talking. And remember one of your customers may be a chemist or something so dont give them all the details! Explain what your going to do how long it's going to take and the price! And never never wreck shop at a customers house when you have to go to the restroom. At a Seminar in GA., a guy that done many of sales pitches for big companies said. The biggest rule you never break is ask to use the restroom! He said if you have to take a S--- go to the store.