I tune all of my engines for maximum power in the air. This is an area where I think there is widespread misconception. There are guys who don't understand how our engines unload in the air who tune for max RPM on the ground. Some of them are racers. They go through engines quickly and have lots of deadsticks. But that's not tuning for maximum power; that's running lean in the air and ruining your engine. There are other guys who think lean=more power and rich=more durability which is also false. Peak tuning is more power, and keeping the RPM's down and keeping the engine cool is durability.
What I do is experiment with various rich settings on the ground until I find the one that gives me the maximum RPM in the air throughout a flight. It's easy enough to hear what the engine RPM is doing after you've been at this for a while. I find out how rich the engine needs to be on the ground to still be peaked at the end of a tank of fuel, and that's how I tune it from there on out. Every plane, engine, fuel, and prop combo is different, so it take a little time to get it right for everything you fly. The old rule of thumb of tuning 500 RPM rich on the ground gets it pretty close to peaked in the air on most engines, but not always. The point though is to find out what your particular engine and plane needs and set it to run its best.