Hey, here's my number

It takes a certain guy to attract my eyes. I'm not shy to voice my opinions about what I find so unappealing about the men living in my hometown. Granted a few catch my attention, but I find it hard to flirt also. But I'll never show that I'm eager or desperate.
It's when I start to feel uncomfortable, that I have problems. I try not to put down a guy, if he is talking to me. I rather be polite and disclose that I'm not willing to give up my personal information.  What do you girl's do in a uncomfortable situation with guys? Also I wonder if any guys reading this have some advice.