How to decrease no shows
Part of the reason no shows occur is people do not fear missing our on something that is free, like a free consultation. Although the consultation has value it is perceived as something that is free from the consumer standpoint. People have a hard time missing out on things that have value. In some cases certain providers take a credit card that will be charged a small fee if they miss the appointment. I do not think that is necessary with CoolSculpting and may be counterproductive. 

So what you need to do is create value in the free consultation. What I would suggest is creating scarcity and urgency by offering a free gift card for a small amount let's say $100 which can be used towards a treatment if they show up ON TIME. You do not want to sound like you are begging them to show up. In fact, you want to show the opposite. Just like nightclubs will keep people out front in waiting in line to create social proof and scarcity. So when you book them on the free consult you could make a statement like. We do a really good job so we are super busy. So if you can show up ON TIME for your consultation I will give you a $100 gift card for your punctuality.

So now someone is much less likely to miss the free consult because it is not free anymore. It has a $100 value. You implemented social proof and scarcity by telling them you are busy which makes them more like to have confidence in you.