This is my Simple Bobble Slouch Hat knitting pattern. It can be knitted in any dk yarn of your choice on 4 mm needles.
This hat when made up has plenty of slouch.

The knitting pattern provides full instructions for 4 sizes Xs, S, M & L so can be made for anyone from babies to adults with a head circumference between 16-24 inches.It even has step by step instructions with lots of photos to help you make the pom pom.
You can buy this knitting pattern here for £2.10 as an immediate pdf download.