Wasted surgery time

I think there is a risk of trying to re-invent the wheel here.

Firstly, only work with patients who value what you do; how you get them to value you, your skills and service is a matter far too broad for this space.

Next ensure you have communicated clearly that when appointments are made they are important for both parties and that they are an appropriate and reasonable time in the future.

Now decide on a means of reminding people when they are due to attend that is right for both sides, egs telephone, email, text all work but not for all people all the time.

Instil a fear of loss into the patient.

I could go on, the basic answer to your question is that no one thing works for every practice or clinic every time and that the important thing is to know your patient, understand their motivations and communicate.