Subtlety is a complicated task for a lot of people. Subtle hints ARE good if you can truly make them subtle. I've been the victim of several girls who would try to be subtle, but would end up flirting their way into "skank-dom." Some would even try to give signals, but kept them too subtle, so it would take a while before I realized what they were attempting to do. By that point, it was too late.
Anyway, subtle hints will certainly lead the guy on, but make sure that he is interpreting them correctly before you lay it on him any harder, because it seems to be a problem for some girls that if a guy isn't interested, she will start flirting more and making it much worse.
Just make sure to give these subtle hints to one man at a time as well. If one catches you flirting with another, he may think you are not really interested.
So, I have a question for girls, why do you wish you could find a guy LIKE me (and other guys)? What is so wrong with me that we click on a level that no other man could and I can only be a friend?