General Export Settings
I export two files, one for YouTube and one for podcast, and used to use the YouTube and Audio Only presets. But occasionally I'd find a periodic pop in the audio for no reasonable reason. It was significant, and deeply annoying.
You may be able to resolve this by switching to Custom settings and changing the render speed down from maximum/100. 50 was what I needed to use to consistently remove the pop, but on DaVinci Resolve free which uses CPU and not GPU this increased rendering time 2-3x. If you're having this problem and have a minimally decent GPU, I'd recommend picking up the paid Studio license which will make use of the GPU and stop maxing out your CPU. It will also make your whole user experience with DaVinci Resolve less taxing overall.
These are the Custom settings I use. Settings that haven't been mentioned are their defaults.
Codec: H.264 / H.265 on DR Studio
Resolution: 1920 x 1080 HD
Quality Restrict to: 50000 Kb/s
I have no rationale for this, someone suggested twice framerate so...
Codec: Linear PCM
Bit Depth: 24
I was having issues with AAC / 16 and this was a suggestion so...
Render speed: 75
With the upgrade to Studio and better performance with the GPU, I could theoretically make this higher, but I'm in no great hurry.
All y'all probably want 4K and all that, but I'm recording remote interviews where my guests on average seem to have 720 webcams. Even though I can record myself in 4K it seems overkill to do anything more than 1080.