My Hair Won't Curl Can you Help? Points are For sure!?

I have so so thick hair, but that's not the problem. I curl my hair starting at the miiddle, curl once around, pull down, then curl all the way to my earlobe length. When it comes out it looks either only a little curled at the bottom ( or mangled!) or striaght! how do i get that cute girly full curls with my curlying iron? :( help? best answer is gurenteed points! to get the points please don't just give me a link, give me full instructions, a link, step by step and what i may be doing wrong. THank you!