DH and I are both on the introverted side, and so are our kids. I can "fake" it and be friendly enough, but it really does drain me. If I know I have to be at a school function or gathering where I have to be upbeat and perky, I take Advil first because I know I will walk away with a pounding headache LOL I tend to be more comfortable when I am the one in charge, and it is important for me to be a visible presence at my kids' schools and activities, so I am usually the room parent, or chairperson of an event, or even a coach - that way other parents are forced to have to talk to me, and we always have *something* to talk about!
I found that using my kids when they were little was an easy way to strike up a conversation with just about anybody. It's harder now that they are older - for some reason 15, 11, and 9 year olds are not so cute! It helps that my kids play sports - I automatically have something to talk about to anyone interested in those sports, or other parents who have kids involved in sports, too. I love to talk about my work, but nobody wants to hear it LOL, and when I am really comfortable with someone and I know they can take my sarcastic humor, I can really start being myself and it is a lot of fun! I am pretty good one on one, or in a small group, but I've never been one for the bar or big party scene. Intimate gatherings are so much more fun for me. Unless I am drinking....then I can handle it. I come from a big family (so does DH) so I think that this has helped me figure out how to both isolate myself when I need to get away from a group of people, and how to break into a conversation/group when I have to.
DH is introverted, but also outgoing, if that makes sense. He can talk to anyone and be friendly and likable and make people feel comfortable, but only when HE wants to. For him it's a choice. At other times, he is perfectly fine to just sit by himself and not talk to anyone. Sometimes I think I want him to be the conversation starter with someone until I get comfortable in the situation, and when he decides that that is the time he wants to be introverted, I get annoyed (j/k - kind of...) that he won't be my ice-breaker! Once I get rolling, though, I can keep a conversation up unless it's someone super-shy who only gives me one-word answers that go nowhere. You can only ask so many questions in a row! If they don't expand or ask any back, I get the vibe that they don't really want to talk, and I excuse myself.
Our kids have a mix of both our personalities. DS15 is very assertive and will not hesitate to share his feelings or perspective on things to anyone. He is a leader. However, he is not a loud, in-your-face kind of person, and he has yet to have a real girlfriend because he never knows what to say to a girl he likes. He has lots of friends that are girls, so I'm pretty sure the block comes when he likes-likes one. LOL It's OK...he has too many other things to focus on right now! DS9 is probably our kid with the most "fun" personality - he will be the one in college with the "Yeah! Let's do this!" attitude. But, he can also be shy. He has the most trouble of the three of them in speaking up for himself. DD is very reserved, but not shy. She has a hard time breaking into a group of girls if she sees them somewhere (even if she knows them), and tends to want to hang around one person at a time rather than a gaggle of girls who drain the energy out of her. Even when she has sleepovers with her group of friends, she will sometimes leave her friends in the family room and come sit with me for a minute just to regroup. However, if she wants or needs something, or has something to say, she will tell you straight out. We are working on her filter...haha
The older I get, the more I am able to express my opinions and thoughts on a subject without worrying about what people think of me. In my opinion, if they debate or disagree back, it makes the conversation more interesting and longer! So, don't be afraid to say what you think...people might surprise you once in a while.