I've always had shoulder length or longer hair that is fine. And I've spent -- oh, hundreds on curling irons through the years. The Helen of Troy brand is the first one I've found that really works on fine hair.
I'm frugal, so I've always gotten the ones that are around $10. But I decided to bite the bullet and get a really good one. After reseraching curling irons on the internet, I went to Beauty Max and was pleasantly surprised to find the Helen of Troy for only $30.
Be careful. It gets really, really hot. It does have about 25 settings, so if you want cooler that's easy to do. It's easy to use, and unlike my hair dryer, the switch is placed where my finger doesn't constantly hit it and change the setting. If you need a good curling iron, try this one at a great price.