Organized a medium sized event all by myself, including contacting a stranger, getting money to bring him in, and then planning all the details of the event!
I spin fire, and I had my first spinning experience where I enjoyed myself the whole time, instead of mostly being nervous about it. Not coincidentally, it's also probably my best performance.
As in Joshua Blaine's original description (below), but may be used to brag about things you've accomplished either this month (December) or the previous one (November), assuming that you haven't brought it up in any earlier Monthly Bragging Thread.