I recently became a master of both the jet and the chopper (excuse my ego)
I use an xbox controller for both. I only really started getting lots of kills in jets when I started to use the rudder.
Before the rudder - Following someone, they make a tiny movement left. To actually hit them with my machine gun I would have to rotate 90 to the left and then pull up to move my aimer left.
With the rudder - You stay level, move the rudder left very slighty and it moves your machine aim, like an actual gun you can move. Revelation!
Also use braking and sharp turn with rudder when getting chased. When flying I'll use 3rd person, but when attempting to shoot something it's always 1st person. I have max upgrades and I use:
Air radar - quite possibly the best upgrade, vital when dog fighting.
Flares - I find these better than the ECM jammer.
Land based missiles - 2 of these + a little machine gun fire will normally destroy a tank.
I don't use heatseeker at all in the jet, they don't reload fast enough compared to flares. Especially when you opponent is ducking and diving to avoid a lock.
As for the chopper, that does take a fair chunk more practice. Half my time was spent learning and judging how far you can lean forward without hitting the ground, that's done purely with practice. I fly 99% with 1st person, it's much easier to learn how far you can push it before smacking in to the floor. Once you get the hang of flying it's very easy to avoid missiles by hiding behind building/trees etc.
When you face an enemy helicopter always try and keep above it. As soon as I see one coming for me I'll jump straight on the ascend button. Use heatseekers but only fire when your fairly close as the flares will waste your missiles.