Doing production tech in some sense is an exercise in risk management and crisis aversion.
Video recording tips
Lessons learnt from recording boo-boos… uh, I mean learnt from 'the field'
Disable sleep mode
Consider recording using clean HDMI output to a PC, over in-camera recording
When doing longer recordings, the Canon DSLR (5D mark iii) will loose about 16 seconds between new files as you record in-camera. For example, this happens whenever the current file goes over the size limit.
You don't need a clapperboard, but clapping does help with the syncing process. Record the audio on the DSLR even if you're doing audio via other means, to help you sync!
Things to check BEFORE uploading to YouTube:
Hold slides for longer, as on playback there will be lag
OBS - do a test recording (output may not be FFMPEG, may have duplicate audio inputs…) or you might have to reshoot it all!!!