Your customers might be coming in to see you because they’ve got a crystal clear idea in mind, but they’re also often looking for some impartial, expert advice on what works and what doesn’t – the sort they can’t necessarily count on (or trust!) from their friends and family.
Make sure you're answering any questions they have honestly and giving them your professional opinion. For example, if they seem keen on a treatment that's unlikely to work for them, let them know politely (and explain to them why), and offer an alternative that you think will work better.
They’ll appreciate it. Remember, they’re trusting you with something very personal. Nothing will leave a bad taste in your customers’ mouths like feeling like just another number.