When you begin playing the game, fly in Europe instead of the Persian Gulf. The missions are a bit easier due to the terrain of the area. Always try to fly along the rivers as you will then be able to go below ground level and avoid being shot at.
At the beginning you may get cheesed off as it is quite hard completing both objectives on your own. If you take a few hits on the primary objective go back to base and you'll still get a decent score. When you get your first commision to 2nd Lieutenant, things get a lot easier as there are another four helicopters flying with you!
You should always set the co-pilot to activate the chaff and flares as he is fairly good at it and improves as your rank increases. When you are attacking a primary target, the last this you want to do is try to jam enemy missiles!
If you aren't keen on getting shot at, fly a Commanche and give the your wingmen Apaches. The enemy won't see you and will fire at your wingmen instead!
When you are on a recon mission, put your wingmen's weapons on hold so they don't blow everything to bits. As soon as the objective has been completed, free the weapons and blow the shit out of the enemy. Always promote your section leaders first as they get shot at more because they're at the front of their unit. As their rank increases, their abilities will increase so they won't get hit as much.
Some targets will require more than one hit to kill, most notably some enemy helicopters and infantry. Rather than waste two hellfires on an infantry site, use hydras as they're very effective. When using hydras you don't have to keep a lock-on for the rockets to hit, you can press Backspace to select another target and fire straight away!
If there isn't a FARP point you can also re-arm back at your base. Sometimes it can be quicker going back to base than going to a FARP. Always try to complete both your primary and secondary objectives in 30 game minutes or less (use the timer at the top left of the HUD) if you take longer than this points are deducted from your score.