How can I get my hair wavy?

Ive just been i the shower, so my hair is still damp. Ive went to sleep in a plait before, and woke up but then i brushed it and it went all static and puffy and not wavy. What should I do to make it wavy.. like this.. http://www.google.co.uk/imgres?imgurl=http://static.becomegorgeous.com/gallery/pictures/brendasonghairstyles_longwavywithhighlights.jpg&imgrefurl=http://www.gallery.becomegorgeous.com/brenda_song_hairstyles/brenda_song_with_long_wavy_hairstyle-671.html&usg=__nSb3-9gUYbow3LqY7sJGdFpG3UQ=&h=354&w=266&sz=73&hl=en&start=0&sig2=ecIvRslDIUd7diw6WQmAcw&zoom=1&tbnid=dWgripBgCyHEoM:&tbnh=114&tbnw=86&ei=3nWTTamDBcyo8AOg9PjpAw&prev=/images%3Fq%3Dmermaid%2Bwaves%26um%3D1%26hl%3Den%26sa%3DN%26rlz%3D1R2ACPW_enGB359%26biw%3D1345%26bih%3D491%26tbs%3Disch:1&um=1&itbs=1&iact=rc&dur=442&oei=3nWTTamDBcyo8AOg9PjpAw&page=1&ndsp=29&ved=1t:429,r:6,s:0&tx=67&ty=42