How do you get these kind of waves?

My hair is kind of thin and straight. I am wondering how to get this kind of wave http://www.wikihow.com/Image:Me-as-cousin-it.jpg ot tight waves like this image http://www.wikihow.com/Image:Peachy-Keen-1.jpg. All i have is a diffuser, mousse, gel, and spray. I dont want braid my hair or put on curles and ext.