First off, let me say that I am far from the best in the game, or even really good. But, at times, with certain strategies, I do fairly well. Other times, I suck. So take these strategy suggestions with a grain of salt. Try them out, see how they work for you.
My favorite role on most of the maps I play (Songhua Stalemate, Sharqi Peninsula, Mashtuur City, Dalian Plant) is as chopper pilot. Doesn't matter whether it's the transport chopper (Blackhawk is the most maneuverable for me, the Chinese version is a dog) or the attack chopper (MI-28 Hind or Apache are both great). Lately, I've enjoyed playing with my squad member ONG_MO as we team up in the chopper. He's usually the gunner and I'm the pilot. It can also help greatly if whoever is the gunner, or just have another person or two jump in) is an engineer, as they can switch back and forth between repairing the chopper and gunning. Repairing while under fire can be dangerous though and will only buy you another few seconds to hopefully get out of dodge.
As the pilot, the best technique/role to take on, is base clearing and flag capping so the enemy can no longer spawn there. Make sure that you are in a squad with your chopper buddy as it helps if your gunner gets shot out of the chopper, he can spawn right back in the chopper. More on that part of the tactic later. Request an order from the commander and go directly to that base. Hopefully the commander knows what he's doing. If your gunner is in the left gun position, approach the base from the right (keeping the base on your left side) at a medium altitude. Commence circling around the outer perimeter of the base using mostly the tail rotor (yaw control) to circle around, keeping the same altitude. The key is to stay steady and level! If there are any fellow RL pilots out there, you are basically executing a turn around a point, where the point is the center of the base. If you have a good gunner, and are able to circle steadily, you should rack up the kills. I've circled once or twice while my gunner, ONG_MO has taken out at least 6+ soldiers. After racking up a bunch of kills, it may be relatively safe to drop in and try to cap the flag. This does work best with more people in the chopper, but is riskier overall as more of your team is wrapped up in the chopper and not on the ground. The best way to come in to the base, is so that your gunner positions are facing the openings where the enemy will approach from. That way, even if you have one gunner, he can switch guns and keep you covered. My choice is to stay in a hover to capture the flag. It makes it much easier to get the heck out of there if someone gets missile lock on you. And I advise you do just that. As soon as you hear the missile lock, hit the throttle and get the heck out of there and get to a safe place to get repairs to come back and try again. Make sure your gunner takes out anyone at the AA missile stations next time. They will most certainly be waiting for you. ONG_MO and I have easily taking 2-3 flags in a row before getting taken out. As I said, it works best if you have some ground support with you to hold the base after you take it. Most likely, there is one or two enemies hiding waiting for you to leave so they can recap the flag.
Let me know what your favorite tactics are. I know my tactic can be controversial, if you read the forums often. Lots of people hate the fact that you can capture flags in choppers. But it can be great fun, and not too bad for points.
Oh, and one last thing. It's kind of personal preference, but I find it much easier to fly with a joystick than with the mouse and keyboard. Some people may argue this, but, I can hover much better if I can just set the throttle to pick my altitude and leave it, rather than having to hit the increase throttle button every second.
