I agree with Josey. I set my curves like this

get it idling as whatver RPM you want. Then without any curve go to full throttle and get it set for MAX RPM minus 200 for in air and start reducing the curves percentage until you just hear the rpm drop then increase a precent or two. Close and open the throttle a few times to make sure you see the same RPM figures

Now using a tach, find half throttle by reducing the stick until you see half the rpms you had at full throttle, set your curve to 50% at the stick position shown on the screen of the radio.

Now set the other points in the mix to remove the high and low spots so your curve is pretty much a diagonal line

To give you an example, my curve for a brison 3.2 looks like this on my 9303

Point L idle 0%
Point 1 10%
Point 2 23%
Point 3 half throttle 35%
Point 4 46.5%
Point 5 58.5%
Full throtlle 70%

I've done it this way tons of times. Once I get used to the plane and find the spot on the stick where it likes to hover then I will flatten the curve in that area

I;f someone has a better method I'm also all ears