So, Let's talk about AA. Having visual on the enemy ships is probably the most critical part
in winning.Similarly, preventing enemy's eyes over your main fleet is a key to success too.
Victory greatly depends on whether you have eyes on the enemy or not, while keeping enemy's
out of your side. If succeed, It's pretty much a guaranteed that your team's gonna win, unless
you have suicidal teammates. This is by no means a individual job, Teamwork is essential in
order to get the most out of AAing. Of course, a good CV players would do this job for you.
However, If he/she is a beginner to CV or too busy microing other squads, then you're on your
own....

1) Know your AA guns maximum range
Shoot as far as possible, remember where the black smoke pops, that's the max range. You'd use
it to determine the 'Golden Angle'.
2) Know your Golden Angle

(An old NF1 AA guide pic by Obst)
Although AAing in NF2 is much easier than in NF1, simply because you don't have to worry
about adjusting angle, this picture could still give you a big picture of what we're acutally
thinking in terms of aiming planes in NF1,which is somehow applies to NF2.
So, what's Golden Angle? It's basically an angle of which you'd able to get the most hits on
a plane flying at default altitude(Highest height). Hence, you should always position youself
properly and hit planes from this area. Fortunately, angles are out of our concern since we're
using auto control here in NF2. All you need to know is where the Golden 'range' is. It's an
area somewhere between your max AAguns range and your ship, as screenshot shown.
Once you figured out where this range is, you're one last step away from shooting down those
annoying planes!
3) Know Where&How to aim
In NF1, we determine our aim by looking thru planes' shadows. But, there's no shadows in
NF2,thus we now determine our targets by looking at the red circle. I'll repeat this, because
It seems like a common mistake that most people are aiming right at the aircraft
itself.''Determine the planes'fight paths and lead your aim accordingly based on the red
circle below the aircrafts,Do not look or aim at the planes''
There're only two attitudes of what the planes would behave. It's either flying straight or
in a circle. Although planes that flying straight is the easier to get a score of and leaving
the circling planes the hardest to get a hit, you're still going to use the same strategy.
Position>Think&Aim ahead>Fire
Position:Golden angle(Or Golden range in NF2)
Think&Aim ahead:Look at where the direction of the plane's flying,imagine where the planes
will be in the next 2 sec, then lead your aim.
a)Planes flying in straight line are the easiest to hit. Under Golden range, you should able
to score a 90% in accuracy.
b)Circling planes: They're tricky at first, practice more to get better hit ratio. The best
way to deal with these planes is to pick a point where you want it to be taken down,the point
where the plane's either facing away/towards you, you'd get a better chance in hitting that
way. For instance, A plane is flying clockwise under my golden range, I'd like to shoot him
down when it passes at the 9 o'clock(west)position in the circle,because this is when he's
facing away from me. Wait until the plane passes the 6 o'clock then BANG, he's down.
This might sounds a bit complicated, I have recorded a short 'Guncam Compilation' video
below.Hopefully,it'd solve out your confusion.
Due to some technical issues, the resolution didn't come out as I expected. Tho, you should still able to see how I lead my targets for both straight and circling planes.

1)Always use gradual fire to increase your hitting rate.
2)You definitely could shoot down planes outside of the Golden Range(E.G Above your head), But it's gonna be a bit difficult. Practice your AA skills under Golden Range and you will eventually figure out how to shoot planes outside of the Golden Range.
3)Golden Range applies to planes flying at default altitude(Highest height), planes that flying lower than default need to use manual aiming in order to shoot it down(Or let the AAW does its job).
4)To DDs/CLs players: You're one of the best AA ships in game, while you're waiting for your torps reload time or for the main guns to be in range, help the main fleet by shooting down planes while they're busy dealing with the enemies!
5)To CAs/BBs players: Your main guns need 9 to 15 sec to reload, that's more than enough time to fire 2-3 AA salvo. You know the rest...