Ask owners if they may get an insurance reduction by having a 10 minute firearms handling class before letting people on the range for the first time. A local range here did this about 5 years ago, insurance went down, quality of customers went up.
Simple class done in a class room not the range:
These are the 4 Universal rules of firearms safety.
Wear eye and ear protection.
Wear close toed shoes.
This is how you hang a target.
This is how you move the target in and out (there is a mock up a booth).
Keep your guns pointed downrange
If something happens put the gun on the counter pointed down range, come get the RSO.
Show them how to hold a handgun, hand them a blue gun, and watch them hold it correctly.
These are acceptable ways to shoot (weaver or isosceles, double taps)and not acceptable ways (from the hip, spray and pray), at our Range (this is a repeat of the waivers or forms they signed).
Brass goes in this bucket, or swept down range, garbage there.
This class takes like 15 minutes, the crew that work there have told me it only took a few people out of using the range.
Approaching it from the aspect of insurance savings to the owner, and wearing a vest may make the point.
Why not ask for the appropriate Personal Pertective Equipment to be supplied by the employer?