These settings are geared toward experienced OBS users. See OBS documentation for an introduction to OBS.
Settings for OBS can change depending on system specs and network connectivity, but the settings below are a good baseline. Please feel free to share different settings if you find improvements.
After opening your stream window, change "Stream from browser" to "Use streaming software."
(Warning: As with other streaming services, do not allow the server URL and Stream Key to be seen in a stream! Your stream can be hijacked if used by others.)
The most significant changes (versus other streaming services) is rate control should be set to VBR and to use a custom buffer. The settings for bitrate and buffer can be changed (increased,) for better higher quality videos, but those listed above are a good baseline.
Please note that x264 encoder is being used (instead of hardware) due to the ability to adjust the buffer.
Here we down-scaled resolution and used 30fps to keep packet size smaller. There is room here to increase resolution or FPS (marginally.)