Use this to hook the elastic from your mask around at the back of your head. It also converts a mask into a hair band. If your mask is too big this will help it fit.
As everyone has different head shapes and ear positions this may or may not work for you but if you'd like to give it a whirl let me know how you get on.
I've heard it can work well with ponytails ...
Ear Saver
£2.00Price