I shoot video with a GoPro Hero 3+ at a resolution of 1440P (4:3, 1920x1440 pixels) and crop the video to HD 1080p (16:9, 1920 x 1080 pixels) in my video editor. By moving the focus to the lower part of the video, the upper part of the video (often showing the rotor blades and drone legs) is no longer visible.
The recommended video speed is 24 Frames per Second. This ensures that you get enough light on the camera sensor and I found that this leads to the least impact of sunlight shining through the rotor blades (causing flickering). If you want to produce slow motion 60 FPS is recommended.
I use the following other settings in my GoPro:
a) ProTune ON (this allows me to correct the color in post processing, using the HDR plugin)
b) GoPro On Screen Display OFF (i have DJI On Screen Display and i don't want GoPro display to overlap DJI OSD)
c) Spotmeter ON
Nice side effect: the original 14.4K 4:3 video feed is displayed well on my 4:3 First Person View screen. On the ground, via the FPV screen, I can see the LED lights on the Drone legs, even when the drone is out of sight.