Best is not defined. (best is the worst opponent of getting things done, good enough and better are much better contenders for the job)
The backwards and forwards going is just a temporal aliasing and the way a 3d app works you get it free of charge. Nothing special is needed to get this just the right rotation speed and sample rate (and thus if you rotate at same speed as the real helicopter and camera would you'd get this). You know most of the time we actually work our asses off not to get the effect ![]()
If you use motion blur akke sure your shutter actually closes once in while.
Now as for the motion blur, you can let the renderer sample like hell, but i do suggest you actually at some point in animation swap over the rotor blade to a texture mapped disk and rotate the texture. Because its way cheaper and will actually look realer for a fraction of the render time. Yes yes reality don't work thatway, but 3d graphics have NOTHING to do with reality, but be prepared to wait 10 minutes each frame if you don't fake it.