Effective working at audio/video editing sessions (avoid fatigue making steady progress)
OK, I'll have a go. Here's my own answer (and advise I should take for myself - which I actually did do to some extent):


Avoid procrastination. Start small. Start with doing something. Don't hold up too high expectations to put yourself off. Good ideas here: http://zenhabits.net/dead-simple-guide-to-beating-procrastination/ (I succeed a bit with this advice, BTW I have no affiliation to zenhabits)
Regularly deliver draft work in a complete state to the customer. This rewards you. It gives them confidence that this is being done. It gives them opportunity to give feedback during the process (to avoid unnecessay work or deviation or disappointment). It gives them something to do on in the event you are delayed later, due to illness or other commitments.
Take breaks.
Track progress to help predict how long the remainder may take.


I'd welcome anyone else's input. I'm really answering here because no-one else has yet. I'd welcome some enlightenment from your own experiences.