Long before Birchbox and Ipsy, Kiehl’s figured out samples create sizzle. Customers flocked to the brand’s stores in the 1990s for the then rare giveaways. Now, most beauty brands and retailers have followed Kiehl’s lead for good reason.

According to marketing agency The Integer Group, free samples are the most influential avenue for encouraging brand testing and sales conversions. The expansion of sampling has changed customers’ expectations and, today, they presume samples are everywhere from inside stores to online. But proliferation hasn’t spelled the end of sampling success. On the contrary, a well-crafted sampling program can yield big rewards for revenues and recognition. There are plenty of potential pitfalls, though, that can potentially undermine an initiative to sample beauty products. Beauty Independent asked beauty industry experts for suggestions on sidestepping those pitfalls and putting samples into the right hands. Here are eight of their best tips: