Give it to them. Straight.
Honestly and without any fluff.
Forget the marketing and advertising techniques you have learnt. Just give it to them straight between the eyes.
Tell your customers - and prospective customers - EXACTLY what you will do for them or their child.
Here are several ways others have done it, I have done it and the result it had...
Video 1 - A heartfelt and compelling reason why this martial arts school is a good choice.
Video 2 - How a simple curriculum made this girl confident in only 4 months. (Sorry about the terrible music). This made my turn-up rate for kids intros 100%. I would just sms them the link with the time they had booked. The video did the rest. It also attracted praise from England, America, New Zealand and Australia.
Video 3 - This one got me 3 enquiries within 9 minutes. All 3 joined the program.
Video 4 - I have always admired TSK.com and the video adverts they do. Polished, professional and a benchmark to aim for.
Your marketing should deliver your promise in a way that the reader or viewer understands how they will feel and look in your program. Nothing does this better than showing your students enjoying their training.