Do some research: Determine if potential employees are trustworthy. Always checks applicants' references. When high school students apply, contact their guidance counselors. A few minutes of time when hiring could save you from thousands of losses due to theft down the road.
Create a caring culture: Treat employees with respect. Having happy employees not only makes the workplace more effective, it fosters a feeling of family that people will not want to steal from.
Balance your drawers: Do a drawer check after every shift to check that the correct amount of money is in the cash register. If theft is occurring this will also help isolate the culprit.
Keep a careful inventory: After each shift, check the ordered totals against the remaining inventory.
Watch what goes out with the trash: Sometimes employees swipe food and beverages by smuggling items out in the trash. Using clear garbage bags makes it much more difficult to smuggle items out in the trash without being noticed.
Investigate problems: If there is a recurring problem when one particular employee is working, try moving the employee to another shift with different co-workers. If the same problem occurs during the new shift, confront the employee.