The nice thing about the F4U and F6F is that what you learn from one will apply directly to the other, as both aircraft have very similar flight characteristics. The F4U has slight advantages in many categories, but the difference is rather negligible for the unperked Hogs (the Charlie drastically outmatches the F6F in firepower, while the -4 is a beast at a whole other level). It really only leaves you with the individual quirks of managing the fuel distribution and sight picture to learn. As far as the Corsair goes:
1) Rudder, rudder, rudder, rudder, rudder. I can NOT emphasize effective use of the rudder enough. I will even argue--and have, time and again--that the rudder may be even MORE important to effective use of the Corsair than the flaps. The rudder on the Corsair is HUGE and has a TON of authority at all airspeeds, even at high speeds where most aircraft have almost no rudder authority at all. The rudder can be invaluable for rolling down on top of an enemy out of the high-yo or vertical extension, and I've surprised more than my share of out-of-phase opponents by skidding a shot in they didn't think I had. Skids, slips, hammerheads, using the rudder to ride the edge of a spin, and to tighten up your roll (especially if you need to roll to the right in low speed, high-power situations).
2) Keep in mind: EVERYONE knows about the Corsair's flaps. Yes, they're some of the best flaps in the game. It also means that everyone ALWAYS looks for the Corsair to try getting slow and putting the flaps down. Without question, the first and universal thing I see in threads asking how to BEAT the Corsair is: "Get him slow and force him to deploy his flaps, then use his poor acceleration and climb against him to leave him wallowing." Personally, I find that the Corsair is even BETTER in more of a mid-speed range (no slower than 250 IAS, up to around 350). Remember, the Corsair is a great turner with flaps, but you have a LOT of tools at higher speeds that you should NOT neglect. The F4U's high-speed maneuverability is exceptional, and while her acceleration and rate of climb isn't great (excluding the -4) she holds on to E tenaciously and can zoom very well. DEFINITELY understand how to handle the Corsair in a full-flaps turn-fight, but don't give up your speed if you don't have to.
3) Like Muzzy said; What you can't out-turn you can outrun, and what you can't outrun you can out-turn. The Corsair has EXCEPTIONAL engagement flexibility. She may not be the best at any one type of engagement, but is versatile and can do them all well. To a point--so long as you manage your E state properly--she can even swing between E-Fighting and turn-fighting at will. Keep an eye out for Ki-84s, however. In my experience, a well-flown Frank is the single most difficult opponent for a Corsair to tangle with.
4) As shiv said, the Rolling Scissors is one of the Corsair's best tricks in the bag. She's not necessarily UNBEATABLE, but she's VERY good at it. Whether you're out in front and want to reverse on your opponent, or your opponent is and tries to do the same to you, the F4U is well-equipped to win that fight.
5) Fuel management is VERY important, particularly for the F4U-1 and 1A which have additional internal tanks. In the 1 and 1A I usually take off with 100% internal fuel a base or two back from the fight. I then burn in this order: Left to 50%, Right to 75%, Left to 25%, Right to 50%, then switch to Main until it's dry. This serves a number of purposes: First, it gives you a nice reserve if your main fuel is perforated (and Main Fuel always seems to be one of the first things to get damaged on the Corsairs...). Second, It gives you a nice reserve of "Go Home" gas. This distribution should allow you plenty of fuel in the wings to RTB, particularly if you need to run like hell and can't afford to reduce speed for cruise. Finally, it helps balance the aircraft and makes her more stable (due to the added weight in the right wing countering engine torque). With the other three Hogs I go 100% internal with a DT or two. The downside of the DTs, however, is that they heavily impact the aircraft's flight performance (more so than the additional fuel weight of the 1 and 1A). And while you can cut away the tanks if needed, you also lose your reserve (can't tell you how many -4's I've ditched after my main fuel got single-pinged by a .303 :-P ).
6) You've got good guns and plenty of ammo to boot. Don't be afraid to take any shot opportunity you have, even if it's a brief high-deflection Hail Mary. The .50cal don't have the individual punch a bank of cannon has, but if you hit your opponent in convergence and at the proper range, even short bursts can be lethal. I've taken wings off P-47s with half-second bursts.
