Keep her faster at first. 300mph is a good speed to start at. Flaps are your best friend, you can kick out a notch at 250mph, where most opponents can't, and few aircraft benefit from rudder pedals anywhere nearly as much as the F4U.
Most important thing is to know the engagement. In large, multi-plane fights you really want to keep your altitude and airspeed up. The Corsair can do some marvelous things low and slow thanks to the flaps, but her acceleration and rate of climb is average at best, so she's slow to rebuild E. This makes you VERY vulnerable in large fights once you've burned off all your E. If you get too slow, or lose too much altitude, disengage until you can regain your position and airspeed. Corsairs will also own most high-speed engagements, as few aircraft are as responsive at high speeds. Rate of roll and cornering above 300-350mph are top tier, and responsiveness remains high up to VERY high airspeeds. She has a large and highly effective rudder, and the Corsair maintains rudder authority at airspeeds where the rudder for most opponents is generally useless. All those Spits and La-7s who think they can escape you in the zoom are in for a rude surprise. VERY few aircraft hang with the Hog in a zoom and I've both run down and escaped many opponents who are superior in a sustained climb. 12,000 pounds of airplane makes for a LOT of momentum and energy retention.
At low speeds the Corsair's flaps are among the best in the game. Though there's some debate about realism (anecdotes and historical accounts say one thing, but pure math supports the turn radius modeling as-is) but while they're there, may as well use them. 1v1 there's few planes the F4U should be afraid of slowing down against (stay fast against Zeros, Hurricanes and the early Spit Marks, especially the I and V). Vertical performance at low speeds ranges from poor (F4U-1) to good (F4U-4) with most of the family somewhere in between. All the Corsairs except the -4 have trouble in low-speed vertical fights, while the -4's uprated engine and big 4-bladed prop can muscle her through these engagements.
If you get in trouble and have altitude, point that big nose to the ground. If you have sufficient separation The Hog's superior responsiveness at high-speed can make a big difference, and though some of the lighter opponents may close distance in the sprint, very few will catch the Hog in an extended dive. Often, those who can will now be fighting to regain control of their own plane while you can pull out at will and trade all that speed for altitude. It's VERY difficult to compress a Corsair (full-power WEP from 15,000ft to the deck can do it) and the airframe is very sturdy, so is unlikely to start losing pieces (only thing I've ever lost is landing gear if I have them out above 475mph).
Personally, I prefer to keep the F4U in a moderate speed range, between 250-350mph and stay above the fight. This way I can take advantage of both the Corsair's high-speed handling, and can still get down to drop a notch of flaps or two if needed. I also set my guns at close range (200yds).