The number one cause of mortality in small dogs is accidents. A Yorkie is at risk partly because it is small, but also because it is a terrier who doesn’t know it is small. It will therefore act just like a big dog in any given situation, including approaching dogs 50 times its size with full professional attitude.
Keep puppies confined to an exercise pen when you are not home, so they can't hurt themselves while you are gone, or chew the baseboards and the corners and arms of your furniture. Yorkie puppies have a thing about shredding paper, so don't bother buying disposable puppy pads, or you will be treated to a snowstorm.You'll need a couple of those cloth diapers they use in rest homes, impervious blue on one side, absorbent white on the other. You can pick them up at a surgical supply. If they develop holes or become split or frayed at the edges, mend them or throw them out, as a curious puppy can crawl between the layers and suffocate. Small bathroom or kitchen rugs should not be used in the puppy pen, as they can be shredded by an energetic puppy which can then become entangled in the loose threads and strangle itself.
For safe car travel during the entire lifetime of a small pet, you will need a sturdy crate. The ideal size is the VariKennel #100. Not too small, not too big. You can seatbelt it into the back seat or fasten it with a bungee cord into the back of an SUV so the dog doesn't fly forward during a sudden stop and isn't in danger from the air bags. In the event of a collision, the crate will also keep the dog from escaping into the road, and it will make it much easier for rescuers to capture your dog and carry it to safety.