Most of what women do to hint or signal is cowardly and stupid. They think that a quarter-second long glance and smile IS THE MOST OBVIOUS SIGN EVER THAT I LOVE HIM AND OBVIOUSLY ISNT JUST ME SMILING OUT OF AWKWARDNESS... which is why guys have to do the vast majority of work to get girls, because if a girl does virtually nothing she still gets asked out.
Me and a guy I like have been staring each other down...straight in each others eyes, and we have done everything short of someone actually making a move and asking the other person out, which I believe the guy should do. So not sure how much eye contact is good to make the point...but in my case, it is great if I plan on entering a staring contest and need practice. xP
im relly sh but if I pas someone in the street and I think theyre nice looking I won't look twice because I don't believe in finding a relationship that way, with guys who are in my classes but I don't speak to I will hold eye contact, but its the guys job to speak first, other girls would judge me for speaking first, I may get shot down also so flirting is the best way to see if I have a chance, with a guy I'm close to I will FLIRT if I like him, I agree eye contact and that only is cowardly however, for girls its our first option and we can tell if a guy is into us or not by that, of course if we think he is interested we will look for more signs, severley doubt our own opinions and wind up waiting for the guy to make the first move, hope I helped, sorry its long