The same safety rules of any shooting practice apply to dry firing. Every once in a while, a user is "surprised" by the fact that they left a bullet in the chamber or did not drop the magazine before beginning disassembly. According to the rule of negligent discharges, the gun will always be pointed at the most expensive or tragic object in the area when it goes off unexpectedly. So always point the gun in a safe direction, even if it is "unloaded."
10) Conflict lubes
Some lubricants are solvents for others. Follow the recommendation of the manufacturers first, and use the same name brand grease and oil if they are both used on the same gun.
11) Use non-coated aluminum cleaning rods
Aluminum rods are generally cheaper and are quite durable. Unfortunately, uncoated ones oxidize and the resultant oxidation can easily abrade steel. In fact, the product of aluminum oxidation is manufactured to abrade steel. This is not what one wants in a gun barrel. For field use, portable field kits from Otis Technology or Hoppe's BoreSnakes are recommended.
12) OK, baker's dozen
What is the worst, most wear-causing thing a person can do with a handgun? One can quickly break an extractor by putting a bullet in the chamber and letting the slide slam home.
The extractor on any duty handgun grabs the back of the bullet when the slide moves forward. This action is cushioned by the motion of the bullet being stripped off the magazine and the fact that the action begins at the beginning of the forward movement. While the bullet is moving forward, the extractor contacts, then works its way around the case rim. The bullet wiggles a little before fitting neatly in the chamber. If this has to occur on a stopped bullet, while the slide is at its maximum velocity, it will eventually cause the extractor to fail.
For clarification, the phrase was "will fail" not "might fail." Even a chipped lip on the extractor will lose a firefight.