Does anyone know how long the string is meant to be to tie around your ankles to keep balance. you can buy it but I think that Im gonna be tight with money on this.

you dont need that just plactice practice practice you need to know yourself stay mobile as possible and still be in punching position

You can do exercises like standing on one leg, even throwing punches on one leg to work on balance.

that string wont help you at all, everyone is different in shape, so the best way you can learn balance is shadow boxing wiht your eyes closed

or you can stand on one leg ad reach down and touch your foot, do it on each leg and that will sort of help you with balance

shadowboxing is the best thign you will learn how to feel comfortable with yoru leg placement