I made the hat below for one of the teachers at work. She'd said she would quite like a cap, and I'd seen this pattern, and had just the right yarn to give the demin effect.
The yarn is Cedifra yarn Selena in three colourways, blue/yellow, blue /pink and blue/blue knitted together with a basic yellow acrylic double knit to get the correct gauge and the mottled effect. The pattern is from The Knitter's Bible of Knitted accessories by Claire Crompton, the pattern is the Weekender Cap from p 88-91. The person it was for was very pleased with it, as I'd made it as a surprise for her.