cable flies aren't exactly best for you...
the one i do is kinda hard to explain but you lay on your back with pretty light dumbbells. take it down like you would for benching them but do a fly motion instead of a push if that makes sense? then when you get to the top rotate your hands 90 degrees so the bells are now both going with your body and do the same thing.
do 10 sets *a set being up and down both ways* and watch your tits grow like a middle school girl
