How do i complete MGS4 without alerts?

idk i bought the stealth item and i just wore it at all costs and prone when near enemies used suppresed weapons... mp5 recommended.... knife too.... dicstractions.....if crying wolf is the girls with the dolls then there is no alert thing... if she is the one in the house place just hide under bed and put sleep gas things.... lol idk if mgs1 dream counts but just dnt get caught in case.....