I want to flirt but im really really shy!!?

i like this guy. hes cute, sweet, and funny but i just cant approach him! i can feel my face burn red when i do and when he does joke around or talk to me and i answer i feel that my words sound like attitude or harsh bu thats not me. i want to be able to talk to him but im just soooooo shy. how can i flirt around with him in a way that wont seem too obviouse or nothing thats way out of my comfort zone and how can i make him notice? what do guys like about shy girls?