1. Tell the quiet person she should smile more 
If you want to make a quiet person feel bad, tell her to smile more, as there’s nothing like being passively shamed into not meeting the American culture’s daily smile quota. The American nation is indeed one of fake laughs, put-on smiles (I’ve worked two office jobs in my life – both of my bosses informed me that I hadn’t learned my Fake Smile yet, which, if I think about it long enough, begins to seem like an insane concept) and objectively erratic behavior to fill silences that have somehow come to mean awkwardness. So – when a quiet person does not smile, the most enthusiastic of us might be tempted to get them back on the train. “You should smile more,” we say, and this perplexes the quiet person greatly, because how the fuck are you supposed to respond to that? It’s a guaranteed loss. Here seem to be the options: a) “Oh, yeah heh, I should,” which is pride-killing; b) “Oh I’m fine, it’s just my face, my face is just this way, I’m happy,” which is in essence a forced apologetic stance for not being excited to the point where one is grinning all the time in social situations; or c) “Oh, I’m fine,” which is perhaps the most preferable of the three, but will likely lead to the questioning party being suspicious that the quiet person is “weird” or a “downer” or something.
2. In a group setting, make a joke that the quiet person is bored or not having a good time
Directing all attention to a quiet person while joking that he is obviously bored and not having a good time is a very poignant, sharp way to make a quiet person feel bad. Quiet people, generally, do not seek such overt, sudden attention and such a statement not only focuses this attention on them like a laser beam, it puts them on the defensive while they’re off-guard, and there aren’t many options for response. The quiet person can scramble into a fake smile: “Oh, no, I’m fine, I’m not bored, I’m having a great time,” nodding his head, to the for-some-reason laughter of the crowd. Or, the quiet person can ‘give up,’ as it were: “Yeah, I’m bored. So what,” which, inevitably, will make everyone else feel bad and definitely isolate the quiet person from the group.
3. Meet people the quiet person doesn’t know and never introduce her to them
Here you can see the quiet person at her most ashamed. Yes – it should be admitted: like everyone, many quiet people have issues, and one of their issues can be Meeting New People In A Group Setting; it would be considerate of you to humor them for this, just as they humor you for your social convention-bending quirks. And so when one person is the ‘gateway’ for a quiet person in a group setting – that is, when one person knows everyone in the group while the quiet person knows no one – it is greatly appreciated when that person has the social graces to simply open the door, as it were; to merely say “Guys, this is Jessica.” Of course, quiet people are completely capable of introducing themselves… I’d hate to implicate them in anything contrary. But the fact of the matter is: take a couple seconds out of your conversational repertoire and introduce a quiet person, because she’ll appreciate it.
4. Ask the quiet person what he wants to talk about
Unless in therapy or some other meaningful emotion-sharing session, asking what anyone wants to talk about should just be banned entirely. As asking someone what they want to talk about is merely an incredibly awkward way to fill a silence which only serves to increase focus on the perceived awkwardness of the silence itself, employing this strategy on the quiet person will be doubly effective in making him feel bad. Understand these things about quiet people: 1) they don’t feel uncomfortable with silence, rather, they feel uncomfortable with others’ discomfort with silence and so often feel, reasonably (out of a considerate manner), ‘forced’ into the world in which silence between two individuals = awkwardness; 2) they don’t say anything when they feel they don’t have anything to say. So asking a quiet person what he wants to talk about (which I admit may not be the most common behavior – I don’t think I’ve experienced this one since high school) will not only compel him to respond with what can only be an awkward statement – something like “Uh, I don’t know, what do you want to talk about?” or “Let’s talk about music, yeah… music” – but, you know, compel him to say stuff he really doesn’t want to. Which would make anyone feel bad.
5. Remark sarcastically that the quiet person “sure is talking a lot” 
Sarcastically showing your frustration with a quiet person by passively attempting to goad her into conversation is a surefire way to make a quiet person feel bad. In regards to this strategy, of note is the fact that the two of you are already at odds just by way of your personalities; you desire a constantly yammering individual while the quiet person perhaps desires a one who’s just a bit less energetic. Of additional note is the fact that remarking sarcastically that the quiet person “sure is talking a lot” instantly brings to the open the fundamental difference between the both of you; the irreconcilable situation with which you’re both confronted. This, of course, is likely to make the quiet person feel bad, and good job for that – you succeeded in bringing her down with you.