Reflections...

TAing is like Pokemon. There are many different types of students, and you become a better TA if you have one of each type (because then you learn how to teach different types of students). Some students are better than others, but if you spend a lot of time with students who start out relatively weak, sometimes they will evolve into more powerful students. As your students fight more battles (aka homeworks and tests), they gain experience and level up (but they can still only remember four moves at a time, which is why you give tests every few weeks). Unfortunately, as my 15-251 students this semester know, POKEMON is NP-hard, and this reduction shows that the TA problem is likewise. However, here are a few heuristics that I've found help:

Make the students like you at the beginning. Teach interesting subjects the first couple times, and include jokes or references to things students find interesting (like Pokemon). Then, the students will be more likely to assume that what you have to say is interesting, and will pay more attention. Give interesting homework problems as well, and students will be more likely to spend time on them.

Be prepared for questions students are likely to ask you. You don't have to know what you're talking about; you just have to make it look like you do. Before office hours, make sure you understand all of the homework problems (and have hints prepared), and the recent lecture/textbook material. If the class recently did a hard proof, be prepared to go over it again. You will almost certainly have students smarter than you at some point, so you need to understand things well enough that you can answer in-depth questions they have. On the other hand, you will have struggling students also, so you should be prepared to give in-depth answers to basic questions.

When explaining mathematical proofs to struggling students, start with the intuition, then the basic structure of the proof, and explain at each step WHY you do what you do at that step; it's really discouraging for someone to understand the proof, but feel that they would have been completely unable to do it on their own.

Don't be afraid to rely on other course staff. If they know something better than you, it's okay to refer students to them instead.