I know FDS states that a man sending mixed signals = not interested in you, but the truth is a HVM who is interested in you will not make it obvious without knowing your intention (I'm talking about men in your social circle as opposed to men on OLD). A HVM will respect your boundaries and without any "green lights" from you, he should respectfully keep his distance away from you. A HVM interested in you may hence send "mixed signals" before pursuing you.
So how can I tell if a guy sending mixed signals is just being flirty due to boredom or is waiting for me to signal my interest before making a move? The thing about signaling my interest is that I don't want to make it obvious. It will be embarrassing if I signal my interest only to later find out the guy is just flirting for fun and is actually taken (I've seen too many taken men flirt with women out of boredom). I don't want to pursue men, but the truth is a HVM will move on if you don't signal any interest in him.
I'm not quite sure what you mean without specifics but I don't think you should be embarrassed about sending signals, even if it doesn't lead anywhere. But I'm not sure what you consider sending signals?
What happens to me is that men smile and flirt, then if I like them, I smile back and show them receptive body language. But then, pretty much every time, they'll blow it by immediately negging me once they see my interest. Then I stop smiling and being receptive. They panic and try to reel me back in, but they've already blown it. I don't see that as an embarrassment to me. They're the one who threw away their chance.
Go ahead and send receptive signals back. If they play with you, become an ice queen. Nothing for you to be embarrassed about.
FDS is not against showing interest, if you listen to some of the old podcast episodes they even have tips on how exactly to show interest without full-on chasing the guy.
Showing interest is not an agreement to date the guy, it's just letting him know he may approach you. If he turns out to be an ass, you're not the one who should be embarrassed. Come at this with an attitude like "how embarrassing for this guy that he's such an ass, oh well, next!"