Not to sound like I'm Captain Awesome of the S.S. Badass - but I get a lot of compliments on my formation flying ability - and I always thank them and say that anyone can do it, and all it takes is practice and concentration - but you've really gotta practice, all the time.
I seems like it's a rather elusive art that many don't seem to practice - most are probably content with just being able to stay in a general area in relation to their lead, and that's perfectly fine - not saying that if you don't fly formation that you suck
It really makes the time fly while enroute to target when you're concentrating on staying tucked in position. Granted it's very challenging but very rewarding at the same time, and it looks really slick.
I always fly at my leads 2:30 to 3 o'clock position (on my screen), because the latency/"position bug" in AH makes me appear further back on his (and everyone else's) screen than I really am - this issue with position is also why your bandit sometimes gets that "impossible" shot, and you think "but he didn't have his nose on me!" - on his screen he did!
So it seems that if I fly that position, it looks right to everyone else. Granted it's more challenging to stay tight when you're line-abreast, but I've gotten used to it.
Obviously small control inputs are key, if you get into pilot induced oscillations, just ease away, arrest the movement and try again. I use rudder to control my lateral seperation from lead, try to minimize any wing mismatch. I'm also constantly working the throttle to maintain exact position - asking for a manifold check from the lead and then setting yours there will not keep you perfectly in position, you'll eventually drift -although that works quite well for combat spread formations, you'll still have to make slight power corrections every minute or so.
If you're on the outside of the turn, you'll need to add a moderate amount of power to stay in position because you have a longer distance to travel (think about running around a racetrack, inside vs. outside lane and why they're staggered). If you're on the inside you'll need to pitch down a bit, roll and reduce power to stay with the lead, using the rudder to correct for any drift toward or away from him.
For the flight leads, it seems to be a relatively common habit to stay full power the the majority of the flight - remember that your flight needs some excess power available over your setting in order to maintain position when maneuvering. So ease the power back to about 80-85%.
For the wingmen - if you're looking to get better at formation flying, let the lead go autoclimb, and fly manually - everyone going autoclimb often results in flights getting quite spread out over time. I always fly off of the lead, my eyes are on him 90% of the time, at the same time glancing around for bandits.
So get out there and practice and don't get discouraged, it'll take time to become proficient, but once you get it, it becomes second nature and you'll have a hard time getting out of formation
Here's a video put together with some formation flying - it should be some motivation!
http://www.youtube.com/watch?v=Qd4O3UIB0gw(I'm flying too low in some of the maneuvers, but you get the idea)
