Torch Catching is the quest that becomes available to you once you've completed Torch Tossing. You can get it in the same place as the quest that came before it, in any capital city of your faction. This quest can seem really hard at first, but there's a trick to it. You should try the quest on your own at least once before reading the trick and see if you can figure it out yourself.
After mastering the art of Torch Tossing, the Master Fire Eater has a new challenge for you: Catch Torches! He supplies you with some Unlit Torches to use in your attempts to master this skill. These torches can only be lit with the bonfires in the capital cities, so don't stray too far from the capitals before you attempt this quest.
Near the bonfire, right click on your torches (or push your hotkey if you chose to hotkey them, which is unnecessary for this one) and you will light one, and throw it high into the air. Your goal is to catch the torch when it comes back down. If you catch it, it will be tossed back into the air immediately, so be ready to catch it again! It doesn't go straight up and down, so be ready to move around a lot. Your goal for this quest is to catch it four times in a row without missing. If you miss it, prepare to face the Flames of Shame! Also, the flames of holy-crap-I'm-on-fire. If you miss just one, you'll need to start over from the beginning until you get all four.
Completing this quest rewards you with five Juggling Torches and five Burning Blossoms. Additionally, completing this quest will open up Daily versions of Torch Tossing and Torch Catching, appropriately named More Torch Tossing and More Torch Catching. The only differences between the original versions and the daily versions is their requirements are more difficult. Hit 20 braziers instead of 8 for the former, and catch 10 torches rather than 4 for the latter.
Now, do you wanna know the trick to completing this quest? Don't try to look up at your torch to follow it. Zoom your camera out and look down at the ground. Follow your torch's shadow, and try to stay a step or two ahead of it. This works best when there aren't a few dozen other people trying to do the quest at the same time. If one city is too crowded, hearth back to Shattrath and try somewhere else. Ironforge and Orgrimmar are likely to be packed full, so try Silvermoon City or Exodar instead.