One way I could think might work, is if you get a waxing client who is not a regular (maybe it is their first time waxing at all, or their first time getting a particular part of the body waxed) then you could ask what made them decide to get waxed. Often, it might be because they have a special occasion coming up, or it might be something more general like they're trying to upgrade their personal image, or they want to feel more attractive, or they have a new boyfriend or ...???? Whatever answer they give, you can probably use that answer as a starting point to suggest other ways you can help them.