The wording is slightly confusing, so you were hired to reduce booster pack theft? Or you are a security consultant and you want to be hired to reduce booster pack theft?
If you've already been hired, then good job. It's not like you need special training or anything, people are gonna steal booster packs and hid them in the usual spots. Maybe invest in some security tag system for large items, stuff that can be deactivated and removed like spider alarm wrap.
If you haven't been hired, good luck, an LGS already barely makes any money employing regular staff, they almost never have the cash to hire a full time security guard, that way expensive.