Many years ago when I was just out of dental school and starting my own practice, I was worried about the quality of my work and what people would think of my abilities. I would stress mostly about impression-taking, and if the lab would have a problem with what I sent them. To assure myself that I was sending them the best, I would pour up models and then painstakingly sit with a scalpel and 27-gauge needle and remove small bubbles and blebs from the stone.
As time went on, confidence in my abilities improved and I felt that I no longer had "prove" myself. I did, however, feel - and still do feel - that there was someone watching when I sent off that very rare impression. This feeling of needing to provide the best impression to get the best job in return is important, and helps to keep you honest in judgment of your own work.
After becoming a CEREC dentist, there is no longer anyone who will see your "impression." It is easy to take shortcuts and just draw that margin line where you think it is. This is a terrible trap to fall into, and will soon lead to failure.
One of the goals clinically, after the prep, is to do whatever is necessary to capture that information clearly. This is the same whether taking an impression or taking images. Laser trough, pack cord or leave your margin high and dry. Whatever your choice, do it methodically with the end result in mind.
Work on building your virtual model the same way you would take a great impression. Don't be complacent and settle on a very tolerant or tolerant camera setting. Start at standard and work to move toward a strict setting. This will assure that your model will be crisp, clean and free of shake. It's the difference between an impression with drag in places or a well-defined, easily read impression.
Isolate well, powder properly, take great images and you will be rewarded with a beautiful virtual model. This will set you up for an easy time through the rest of the design process, including getting the best proposal the software can give.
Even though the means to the end will never leave your office, practice like you have someone watching over your shoulder. Strive for the best and sleep well at night.