I’ve always found it challenging to decrease a beanie fittingly. So why not start at the center, in the “north pole” and increase. Found the formula in a Finnish knitting book ‘Suomalainen myssykirja’ - Finnish Hat Book.

It’s simple: cast on 8 sts, increase every other row 8 times per row until you have enough sts for the head circumference. Then go on straight as long as you like.

This is an adaptation of the formula for a child’s hat or a small woman’s one. Knitting it I tried out increasing every row and it didn’t look bad. I used some worsted yarns from my stash and you can use any of yours.

In the end of the instructions there’s an adaptation knitted in sock yarn, gauge 32 sts = 10 cm (4 inch), for a smallish man’s head.