Paper training is a good potty training technique for your Shih Tzu puppy, since tiny bladders can't go long between potty breaks, and small puppies don't excrete too much to be reasonable for a person to clean up regularly. Many people train their Shih Tzu to use a paper that is kept in a litter box or other contained area and which their dog uses for the length of her life. This is a good idea for mobility challenged people who can clean up the pad easier than they can take their dog outside. It is also good in areas of inclement weather, when owners don't want their Shih Tzu's luxurious coat to get wet, or they worry it is too cold for such a small dog to go outdoors.
Always have yummy treats available to reward your puppy for going in the right place, and if she goes in the wrong place, simply move her to the right place or put a paper under her while she is going, and clean it up very thoroughly. Keep your puppy contained in areas where urine will not soak into carpet or flooring, even while you are watching her, for the first few weeks.