I often, well almost always, mix and match my yarn. I start with one of my Hand Spun Alpaca Art Yarns and select other yarn based on the colors of that yarn. The hat pattern I use over and over is Loving Georgia Lee Tyler by Christine Marie Way Tyler & John Wesley Tyler.
I have made many, many shapes and sizes and colors and styles of hats using this pattern. I can’t say I always follow the pattern exactly, but instead pick up whatever size hook seems to fit the yarn I’m using and try it on frequently for size while I’m working!
With some of the same yarn I crocheted a pair of Texting Mittens, also known as Twittens ( I just learned) for toasty texting!!