I fail in group settings, but do extremely well in 1 on 1 settings. The best way I have found to get someone to open up to you, is to first open up to them. Tell them a short but entertaining/embarassing story about yourself and then ask them about something embarassing they have done. Tell them of a not too graphic sexual escapade of yours and then ask them about theirs. Tell them about a fantasy, then ask them about theirs. Tell them about anything extremely personal and then ask them about themselves in that same respect. This way you break the ice by going there first yourself, and then you ask them to talk about themselves afterwards (because everyone is more interested in talking about themselves than hearing about something else).
Smiles, light touching (shoulders, arms, ect), hugs when you see someone the first time, any sort of affection can go a long way in getting someone to open up. I ALWAYS give a good hug on a first date, and compliment the girl on her looks. This can go the same way back to the guy. Give em a good ol chesty hug and tell him that his arms look good, or that his chest was solid. Something to give him an ego boost at the same time that your chesty hug arouses him. A guy with a boner is always MUCH more interested in conversations.
Lastly, since I am not usually that talkative, I suggest movie/dinner dates for first dates. During dinner, if you feel awkward you can start eating while you think of a conversation starter. Its not like coffee where you are sipping for an hour to stall. Movies are WONDERFUL because you can just sit back, relax, and throw your arm around a girl. That second I know if she is sexually interested in me - and whether or not I should even bother getting her interested in my personality. For you, if a guy doesn't put his arm around you, just cuddle up a bit to his side and see if he catches a hint.
You don't need to be the life of a party to get a second date. Lots of guys are also quiet, or are more of a home-body than a witty energetic bar hopper socialite. All you need to do is show affection and attention, as well as peak their physical interests. I melt when a first date seemingly trusts me as a person instead of being apprehensive about a date with a stranger, and visibly seeks my affection in a physical way. I like the feeling that I get when a girl after only knowing me in person for 5 minutes starts to treat me like she has known me for a long time. You don't have to get naked and fuck or anything right off the bat (although we don't mind it), but act somewhat like a girlfriend instead of like a stranger.
Just the same as when at a job, you act and dress for the position you want instead of for the position you have.