You might want to put these ideas into action:

1. Raise Security Awareness with all staff. Ensure they work the salesfloor (where the thieves hang out) and are not stuck solely behind the counter! Good customer service is the key. Approaching someone with " Is there something I can help you with? I couldn't help but notice your interest in our sunglasses/lipsticks/shoes/shirts/tops etc etc... Perhaps I could show you a colour/size/demonstration etc etc?" Opportunistic shoplifters HATE being singled out and tend to leave your store rather fast. Which, after all, is exactly what we want them to do!