1. Never work alone at a gun shop.
2. Never leave an employee alone in the store.
3. If the owner can afford it, he should hire at least two employees. That way they can take turns going to lunch, and there will still be at least two people in the store.
4. If you run a low volume store and can only afford one employee, you and the employee should pack a lunch every day and take turns eating in the store.
5. Everybody working should open carry a loaded weapon in the store. That way any thug(s) casing the place will know you're armed and ready.
6. The owner or an employee should never open or close the store by themselves. At least two of you should approach the door at the same time to open it in the morning. Also everybody should leave together when you lock up in the evening. Keep your eyes peeled.
7. Pay close attention to everybody who comes in the store, especially groups of three or more. Whenever three or more people enter the store together, everybody working in the store should spread out some. Don't stand close together. Be cautious and alert, but not paranoid.
8. If a group comes in and wants to look at some guns, don't just hand them several weapons at the same time. Show them one or two weapons at a time, then put them up before you let them handle a couple more weapons. Never let them handle more than two at a time.
9. Don't let customers and the public use the restroom. Politely inform them it's private if they ask.
10. If you can afford it, be sure to invest in a good electronic security system, including silent alarm and security camera(s).