If you are considering going to Phase A, here are some things you should be doing to ensure your success:
*Memorize your teaching points. I wrote out copies of the points - all of them - on flash cards & used them to study. I probably made a total of 4, maybe 5 sets.
I tried a million different ways to say things, but my instructors always brought me back to the basics. Simpler is better. No one but The Pen & I had been drilled on the points this way, and it made it more difficult for them when it came time to teach.
*Practice teach in front of your instructors - a lot. This is a nightmare. It was my least favorite thing to do. Flopping around like a flounder in front of people who are very good at what you still suck at is no fun, but if you can do it right in front of them, you can do it right in front of anybody.
*Teach real students in a real class. You will do make more stupid mistakes than you ever thought possible. Good for you. Now is the time to do that.
*Teach when you are exhausted, because then your brain is not functioning properly. The Gentleman used to put me through a particularly horrific training session where he would wear me out with a general workout, then make me strike the heavy bag while he continually whacked me & dragged me away from it, forcing me to fight to get back to the bag. Then he'd start non-stop chokes, hard. Then, when I was really having to force myself not to beg him to stop, he'd yell, "Teach choke from the side, NOW!". This single tactic was one of the most useful things I practiced, because in Phase they will wear you out past anything you have ever endured (unless maybe you're in the military), and still expect you to perform. So you might as well get used to it.
*Train with people who have no problem tormenting you and screwing with your head. The Gorgeous Bastard specialized in mentally torturing me (all for my own good, I can assure you), while Relentless & The General loved to tell me to prepare to teach one thing in front of the class, then at the last possible second tell me to teach something totally different RIGHT NOW. All this was enormously helpful to me, as a great portion of getting through Phase is mental. You have to be like the Black Knight in Monty Python's Search For The Holy Grail. When your Phase instructor chops your arm off, you simply say, "It's only a flesh wound!" and keep going. This is easier said than done.
*Learn how to eat, drink, & supplement in the best way to support your body. Then make that a habit well before you leave.
*Train hard and do it consistently. I think I only missed one session in 8 months, when I went out of town. That day was awesome!
*Decide before you go why you're doing this, and you'd better have a damn good reason. It's not fun. It's hard. It's painful. The odds of you being injured are high. Having a meaningful why makes it possible to get through the horrible how.