What is the best way to hint to a girl that you are interested in her??

I am 15, attractive and shy. ive neva asked a gurl out before (but i have had 3 serious girlfriends), and i need help breaking the ice with girls i rarely talk to.im not sure if ill be able to take it from there......but if i need more help (and you guys give me good answers) then ill post a new ?.....hope you guys help, and thanx