One-size beret - How to enlarge it?

You bought a one-size Basque beret and you don't know how to adjust it to your head size?

It's very simple, you take it in your hand at the inner rim and stretch it between your hands.

If that's not enough, you can use your knee to stretch it with your hands by gently pulling it towards you.

Here is a very comprehensive video from the French beret specialist, Laulhère, which explains it: