I figured MBTI was more technical than you wanted, but it's a real world personality typing method that could serve as a foundation. From there it's all basic engineering, in other words, take out everything it will still run without. When it's as simple as it's possible to get, you have most of what you need.
I'm far more interested in descriptive Adjectives that the GM could use without a dictionary!
Google Myers-Briggs and chase some links, you'll get plenty. Still, that gives you 16 possible results, and it's easy enough to find out what average percentage of the population any given type is, which lets you know how much weight to give each of the types in your random rolling range.
For that matter, check out the Keirsey Temperament Sorter, closely based on the MBTI:
http://en.wikipedia.org/wiki/Keirsey_Temperament_Sorter
Halfway down the page is a table that gives you the 16 types and give them a type name, rather than a letter string designation, eg Teacher, Counselor, Champion, Healer, etc. Follow the links on that table and it gets better still, for example:
Teachers are introspective, cooperative, directive, and expressive. They tend to look for the best and to expect it from those around them.
Attitude, how he/she feels today.
Piece of cake. Make a rough scale from "worst day
ever" to "I'm on top of the world", keeping in mind that it's going to have a fairly serious bell curve, meaning the results in the middle are going to be much more likely than the extremes.
By outlook, I mean a broader sense of where the character is trying to go in life, and how he perceives the world and those in it.
I'm still not quite sure what you mean by this. Most of that I'd expect to be defined by personality, although I suppose you could use that to represent changes rung in on the basic "1 of 16 types" by his personal history(like Attitude, only over the course of his life rather than just today). No matter how nice a guy he is, he'll only get screwed the same way so many times before he'll take steps, you know?
They tend to look for the best and to expect it from those around them.
That attitude can be beaten out of you if life hands you lemons enough times in a row.