How to get wavy hair?

I want wavy hair.. like not messy but not perfect waves. like this a href="http://www.glamourhair.com/images/pophairextensions/HH-ClipIn-Extensions---Wavy.jpg" rel="nofollow"http://www.glamourhair.com/images/pophai…/a or a href="http://www.hairresources.com/images/sce/IceGiseleBundchenlongwavy.jpg." rel="nofollow"http://www.hairresources.com/images/sce/…/a I have straightish-wavy hair, medium legnth and dark brown. If i let it air dry it poofs though=/. Any ideas or ways please ! thank you1