A cast-on edge can sometimes look and feel a bit tight but a tubular cast-on has a natural rolled edge which fit the look I wanted for this hat. I had never worked one in the round in 2x2 rib before, and couldn't find a single online tutorial for the exact effect I wanted. A mash-up of several different ones resulted in the following. The pattern will link to this tutorial once it is ready, but meanwhile, I hope this step-by-step photo guide helps in your own hat knitting.
This tubular cast-on begins with a crochet chain provisional cast-on. For the purposes of this tutorial I am working with a 20-stitch tubular cast-on as an example. Obviously a hat for an adult will require substantially more than that! The tubular cast-on starts with only half the final number of stitches, and the remaining half will catch us up later on. Confusing, I know, but trust me, it works.
Since I want a final total of 20 stitches, I begin by casting on 10 (half of 20). To begin, use waste yarn to make a crochet chain around 6 chains longer than the number of stitches you are going to cast on.
To start, slip the first two stitches from the front needle (the one closest to you in your left hand) purl wise on to the new needle. (You can slip them together or one by one, that doesn't matter, just as long as its the first two stitches from the front needle)
As you can see in the photo above, the working yarn is now at the right hand end of the work, but the needle tip is at the left. It is an easy job to just slide the stitches along the cable to the other needle tip so that they are ready to knit, and your working yarn will be at the correct place for you to carry on.