Used Andrea Mowry’s video to cast-on :
https://www.youtube.com/watch?v=ePELhLO2180

It was not easy to follow gauge : 5 stitches in 2.5 cm. So if I follow instructions : 88 stitches total for this beanie in 4mm needles.
But, for example, my Oslo hat had 104 stitches total in 3.5mm needles.

So I was a little bit confused about what to do. So I decided to increase to a total of 120 stitches to have a slouchy beanie. It worked, but I think that you need to have an another beanie to find out what stitches in total you need for your head.

I never do gauge, so I won’t blame pattern.