Wear gloves! If you're going to wash a few dishes or go out bike riding or cook a meal for your family, slip on a pair of rubber or cotton gloves to protect your fingernails. That's basic prevention, but it's probably the easiest way to save your manicure, short of not using your hands at all.
The other thing you can do is apply a clear topcoat every day or two: it'll help the polish underneath stay protected. Make it a thin topcoat: get most of the polish off the brush, then put on a light veneer. If you put on a thick coat, it may just bubble off and take some of your professional manicure along with it.
If your manicurist is on the ball, you're starting out with perfectly polish-free nails and cuticles that are softened and pushed back, so polish doesn't ride up on them and then chip off. A base coat should be applied, and coats of polish should be given time to dry and bond to the nail and to previous coats. Some manicurists also wrap the tip of the nail in polish, slipping some underneath the top edge for better staying power.
