Just read a post over at Keith Lango's blog about what to spend time on when making a short. With my short just finished, I have to say, I totally agree!
I did Animation Mentor full time (mostly) and spent about 12-15 hours a day for the last 6 months at AM. I thought class 5 where we "only" were developing the story, was going to be an easy term. No animation, just come up with a story and develop it. Simple eh? Man was I wrong. It was a hell of a term and maybe the hardest of them all. Creating a story that I (and my mentor) was happy with was so hard. Cause I got really blind very fast and with contradictory feedback it got even harder as the story was developing. Still the feedback is totally necessary, cause you want everybody to get the story. It's always clear to the storyteller, but not necessarily to the audience.
When my story was locked (mid-term class 5), I was warned by many and rightfully so, cause my story involved some visual effects like the transformation from the old guy to the young man. I told myself at that point that Class 6 was going to be animation only. I wouldn't spend any time what so ever on anything else but animation in class 6. I knew there was going to be a wedding right after Class 6 was finished and that it was only 1 month before we was leaving for Siggraph - hopefully bringing my short with me. That meant I had to figure out all the effect-stuff, the modeling, the backgrounds etc before I started animation. It wouldn't be time for it after. If I wasn't able to finish all the non-animation stuff before I started the blocking, I had to go for plan B (which I had) that was a cut-down version of the story with no effects. I did figure it out and when I was done with class 5, I had an animatic with all the effects, all the temp-sound, the backgrounds etc. There's nothing great about those effects, but it gets the story point across :)
Class 6 was animation only for me and I was lucky to have a mentor that was focusing on animation only. After class 6, I spent only three weeks putting on procedural textures and render it using a very simple fake GI light-rig.
At AM we're under a very strict deadline, which is really good. We simply have no choice but to make all the non-anim stuff simple. If I was going to attempt anything like the Ratatouille-sets (ref Lango's post) for my whole short (1 min 10 sec actually screen time), it would have taken me decades to finish and the motivation would have been gone long before that and the film would probably never been finished.
The purpose of my short is to get a job as an animator. And because of that, focusing on animation was really important to me. My short has about 1 min of actually animation and doing that in one 3 month term was really hard (AM recommend 30 sec max for a 3 month pace). It took 12+ hours a day, every day. It is possible for a while, cause it's sooo much fun doing it, but there's only a certain amount of time you can keep up with that before you crack.
Of course we're all different and some people have crazy talents, but to me, Lango's post is spot on and something to keep in mind when doing my next short. :)