Even then you have to make them fly like colossal hummingbirds and create hurricane-force winds all around them. Isaac Newton is a harsh master.
Depends on how far you're willing to go. The fundamental problem for dragons is the square-cube law. Basically, if you multiply the dragon's length by X, its flying efficiency is divided by X*. So if you're going to invoke magic to make it a better flier, your magic needs to increase its efficiency by a factor of X.
Let's start with a real-life animal that's roughly where we want dragons to be. Quetzalcoatlus is all very well, but I prefer my dragons a bit more robust. Say we use Haast's eagle, a very big extinct eagle that hunted moa: Weight up to 30 pounds, body length about 4 feet, wingspan up to 10 feet, able to take off from the ground.
How big should dragons be? Let's figure the tail is extremely long and thin, more of a steering vane. For the body, say 40 feet. That's on par with the very largest minis (8x8 base). So, this dragon is 10 times the size of Haast's eagle in every dimension. Thus, it must be 10 times as efficient a flier.
Assuming we want to make the dragon fly without direct levitation, there are two options: Increase its strength (muscles, bones, and tendons) to support bigger wings, or make it lighter. So, let's double the wingspan and cut the weight to 20% of normal. The dragon now has a 200-foot wingspan, and its flesh has about the density of balsa wood. If you pick up the scales or bones of a dragon, they will seem to weigh almost nothing, but they will be nearly impossible to break or bend. Its blood is some weird liquid, far less dense than water, and probably quite volatile when exposed to air.
Now, this dragon does not look a lot like the typical fantasy-art dragon. It's not a sauropod with bat wings glued to the shoulders. This dragon is proportioned like a bird. It has a tapering body with a huge chest, and vast, massively-muscled wings that spread out to near-absurd length, the membranes extending to well down the tail. Its legs are spindly, mostly bone and talon, and its tail is a long thin whip rather than a big heavy crocodilian thing. It looks like it should weigh 15 tons, but in fact it weighs only 3. For all its size, it is scarily fast, its light weight and supernaturally-strong muscles allowing it to move at lightning speed.
It's a different vision of dragons, but I rather like it.
*The dragon's wing muscles are stronger by a factor of X^2, proportional to the cross-section of the muscle, and its wing surface is likewise X^2 larger. But its weight has increased by a factor of X^3. Divide X^2 by X^3 and you get 1/X.
