As the one and only person in my family that loves thrill rides, can I just say that some of those things don't work.

At least not for my family.
Stuff I noticed:
~If the person gets motion sickness, just forget it. My dad rode Alpengeist (an inverted roller coaster at Busch Gardens Williamsburg), and while he says that it didn't scare him, he was sick after riding it in the front row. Oops. I think coasters without inversions might be better for someone that gets motion sick.
~If they're scared of heights-or, as in my sister's case, scared of falling from heights-try something like Rock'n'Roller Coaster where you can't tell what height you're at. Not something like Apollo's Chariot at Busch Gardens Williamsburg, which my sister informed me after riding in the back, felt like falling into a black hole in the first drop. (It does not feel like you're falling into a black hole, by the way.

It feels like you're flying.)
~Some people hate that stomach-droppy sensation....so don't bother trying to take them on a drop tower or Griffon or Intimidator 305 or anything similar. I think it's cool, but my family hates it.
While I've convinced my sister to actually enjoy some smaller/medium sized coasters, she won't go near Griffon, Manta, Intimidator 305, drop towers, or anything else like that. I think there's a limit to how much you can "make" someone like thrill rides.

I would rather ride alone than not ride at all, so if you love thrill rides and you're with a 'ride chicken' in your group, just ride alone.
Also, PLEASE PLEASE PLEASE don't give running commentary during the ride! I've heard it before and it makes me want to barf, especially when they're not even calling the element the right name. Or are misrepresenting the ride. Once I heard a dad telling his kid that Apollo's Chariot was just like the log flume Le Scoot. UM IT IS NOT. NOT EVEN CLOSE. I don't know if that kid liked the ride afterwards or not, but that was just an out and out lie. I would have been seriously mad if I were that kid whether I'd enjoyed the ride or not.
ETA: Also, I'm not positive, but I'm pretty sure holding your breath during drops isn't such a hot idea. You do that and the postive g's at the bottom of the drop might catch you off guard and it'd be hard to breathe...I said "might", I'm not positive.

I think screaming is a better idea.
