In my new 'old' embroidery book I found the perfect stitch to make waves. It's called the scroll stitch and it wasn't too hard to master. I put the book (and the diagram) upside down because I'm left handed and it actually worked out just fine! Look here and here to learn more about the scroll stitch.
On the photo you can see a little bit of the new pattern I'm working on. It involves a hedgehog, a teacup from my grandmother and a teaspoon. :)