There are facial exercises to firm your facial muscles (Eva Fraser has written at least a coupla books on the subject) but they won't really give you cheekbones where you haven't got any to start with. I'd go to a make up lesson site or buy a magazine/book and learn how to apply blusher properly to give your face some contours...I can't help with that as I don't wear it! Incidentally, I also have a round face wih no discernible cheekbones, and I've stopped worrying about it, I just learned to make up my eyes really well to draw attention to them and not my cheeks.