I finished Ben's hat - it's hardly a piece of design brilliance, but it does fit the brief. I started with this pattern, and then changed it completely. For starters, it's for a toddler, but Ben's head is the same size as mine. So I had to guess how much bigger I needed to make it. I took a punt and cast on my stitches.
Also, Ben didn't want contrasting colours, and I figured a brim that looked exactly the same as the rest of the hat was going to be a bit dull, so I decided to change it to k2p2 rib. Of course, better knitters than I have already spotted the flaw in this plan - it's a good idea to decide what style of pattern you are using before you decide how many stitches to cast on. For example, if your pattern is 4 stitches long, it's a good plan to have a multiple of 4 stitches cast on. But that would be dull, really.
Finally, the pattern wanted me to switch to straight stocking stitch at the point at which it starts to decrease - but since I already had two stitches, I didn't want a 3rd, so I randomly decreased in k1p1 rib. It looks a little odd because I didn't put any thought into it, but it doesn't look terrible. And most importantly, Ben likes it, and his head fits into it.
Finishing this clears the way for me to start a new project (wouldn't like to have less than 5 or 6 on the go), which is a shrug for me. I'm about a third of the way through it at the moment.