A good audiobook or documentary on TV, and a matter of breaking everything down into single, easily repeated movements helps to protect one's sanity. But I wouldn't do this everyday for any prolonged period of time. It is pretty brutal on the neck
Oh: And keep a good supply of paint and fresh brushes. I've found that old brushes and attepts to conserve paint slows down the process quite considerably. It's a bread and butter thing, so I think it is important to treat oneselv with intresting one off projects in between these painting sessions.
It is funny: When I did my very first Space Marine stands almost 20 years ago, it took me ages to paint a single stand with proper shades, highligts and details. Today I reckon I could paint an entire company in the same time and still have it look better. I guess it is all a matter of experience and application of the right techniques. But obviously theres a huge difference between painting somehting to look "good enough" and painting something complex, that involves many different techniques. For example it would be impossible to speed paint a split color scheme like the Storm Lords Space Marines. It works best with murky camo and monochrome schemes. I wouldn't even attempt to paint this ammout of miniatures in a complex scheme!
I remember Tuffskull (Where is he nowadays anyway?) did a speed painting challenge for himself back when we were still playtesting E:A. He did a pretty nice guide that I think would be very usefull for new players who just want a basic army to start playing. The painting guides in the old rulebooks are nice, but not really that speedy. Perhaps we should do some sort of pinned thread of "ultra fast painting tips, for players in a hurry"? There's plenty of guides for advanced painting techniques, but it might be fun to see what tricks people got up their sleeves when things have to be done quickly.